Optically-based nanopore analysis with reduced background
8 claims: 8 independent, 0 dependent
- 1ポリヌクレオチドの配列を決定する方法であって、 (a)第1の側面および第2の側面と、(b) 固相膜およびそれと同一の広がりを持つ不透明層と 、(c)複数のアパーチャーと を含むナノポアアレイを提供するステップであって、前記 固相膜 は、 前記ナノポアアレイの前記第1の側面上の 第1のチャンバーと 前記ナノポアアレイの前記第2の側面上の 第2のチャンバーとを分離し、各アパーチャーが、前記第1のチャンバーと前記第2のチャンバーとの間の流体連通を提供し、シグナル発生領域を有し、前記不透明層が、光が前記ナノポアアレイを通過することを実質的に防止するステップと;前記アパーチャーを通して前記第1のチャンバーから前記第2のチャンバーにポリヌクレオチドを通過させるステップであって、 (i)各ポリヌクレオチドは、 ポリヌクレオチド 鎖 の異なる種類のヌクレオチドが、区別できる蛍光シグナルを発生する異なる蛍光標識で標識され たポリヌクレオチド鎖を含み 、 (ii) 前記アパーチャーのそれぞれが 、各前記 ポリヌクレオチド 鎖 のヌクレオチドを拘束して、 各アパーチャーの 前記シグナル発生領域を一列で通過させ 、 (iii)各ポリヌクレオチド鎖の前記蛍光標識は相互に自己消光性であり、そうすることで、前記標識が前記シグナル発生領域の外側にある場合に励起された相互に自己消光性である標識からの蛍光シグナルは消光する、 ステップと;励起ビームで、前記ポリヌクレオチド 鎖 の前記蛍光標識を、それらが前記アパーチャーの前記シグナル発生領域を通過する際に励起するステップ であって、前記励起ビームが前記第2のチャンバーを通して前記ナノポアアレイに向けられ、それにより金属層が前記第1のチャンバーにおける光学標識の励起を実質的に防止する、ステップ と;前記シグナル発生領域における前記蛍光標識からの蛍光シグナルを検出するステップであって前記 ポリヌクレオチド鎖 の特性を決定するステップと;各アパーチャーの前記シグナル発生領域において検出された前記蛍光シグナルから 前記ポリヌクレオチド鎖の ヌクレオチドの配列を決定するステップとを含む方法。
- 2前記不透明層が金属層である、請求項 1 に記載の方法。
- 3前記金属層がアルミニウム層または金層を含む、請求項 2 に記載の方法。
- 4前記アパーチャーのそれぞれの前記シグナル発生領域が、前記第2のチャンバーに最も近い前記金属層の表面から前記第2のチャンバーに延在する、請求項 2 に記載の方法。
- 5励起および検出する前記ステップが落射照明システムとともに実施される、請求項 2 に記載の方法。
- 6前記ナノポアアレイの前記アパーチャーのそれぞれが、その中に固定化されたタンパク質ナノポアを含む、請求項 2 に記載の方法。
- 7前記タンパク質ナノポアのそれぞれが、前記アパーチャーを横断して配置された脂質二重層に固定化される、請求項 6 に記載の方法。
- 8前記蛍光標識がアクセプター標識であり、前記励起ビームが前記アパーチャーのそれぞれにおいてドナー標識を励起し、前記ドナー標識が、前記アクセプター標識を、それらが前記シグナル発生領域を通過する際に励起する、請求項 2 に記載の方法。
Independent claims8
93 paragraphs, as filed
This application claims the priority benefit under US Provisional Patent Application No. 62 / 279,503 filed January 15, 2016 and the same No. 62 / 308,145 filed March 14, 2016. All of these provisional patent applications are incorporated herein by reference in their entirety.
(Background) DNA sequencing techniques developed over the last decade have revolutionized biological science, such as van Dijk et al., Trends in Genetics, 30 (9): 418-426 (2014). However, the full potential of the technology can be overcome, including reducing sequencing costs per run, simplifying sample preparation, shortening runtimes, increasing read length, and improving data analysis. Many challenges remain to be done. Single-molecule sequencing techniques, such as nanopore-based sequencing techniques, can address some of these challenges, but these techniques present a set of technical challenges of their own, such as reliable nanostructures. Production, control of DNA migration rates, obscure nucleotide identification, and detection and processing of signals from large arrays of nanoscale sensors, such as Branton et al., Nature Biotechnology, Vol. 26 (No. 10): 1146 ~ 1153. Page (2008).
Optical detection of nucleotides has been presented in the field of nanopore sequencing as a possible solution to some of the technical challenges, such as the difficulty of collecting signals independent of large arrays of nanopores. However, overcoming background noise in single molecule optical detection in fluorescence-based signals remains a significant challenge. This has led to the frequent use of microscopic systems such as total internal reflection fluorescence (TIRF) systems, which minimize background excitation, but make detection systems more complex and expensive. In view of the above, if methods and devices that can address the background problems of single molecule analysis using simpler and cheaper microscopy systems become available, nanopore sequencing based on common nanopore sensor technology and optics will be available. Would be advantageous for that particular application, such as.
<p><nplcit num="1"><text>van Dijk et al., Trends in Genetics, 30 (9): 418-426 (2014)</text></nplcit><nplcit num="2"><text>Branton et al., Nature Biotechnology, Vol. 26 (No. 10): 1146 ~ 1153 (2008)</text></nplcit></p>
<p>Abstract of the Invention The present invention is directed to methods and devices for single molecule analysis using optical labels and nanopores. In one aspect, the methods and devices of the invention are intended to reduce noise in the optical signal generated as the labeled polymer analyte passes through the nanopores.</p><p> In some embodiments, the invention provides a nanopore array comprising: (a) a solid phase membrane and an opaque layer having the same spread as the solid phase membrane, wherein the nanopore array has multiple apertures. The first chamber and the second chamber are separated, each aperture provides fluid communication between the first chamber and the second chamber, has a signal generation region, and has an opaque layer. A step that substantially prevents light from passing through the nanopore array; (b) a step that allows the polymer to pass from the first chamber to the second chamber through the aperture, and each polymer is attached to it. With one or more optical labels capable of generating an optical signal with at least a first wavelength that is characteristic of the polymer; (c) with an excitation beam having a second wavelength, the optical label of the polymer. The step in which they are excited as they pass through the signal generation region of the aperture, and the optical label in the detection region generates an optical signal whose first wavelength is different from the second wavelength; (d). ) The subject is a method of determining the properties of a polymer, such as a polynucleotide, comprising the steps of detecting an optical signal from an optical label in a signal generation region and determining the properties of the polymer.</p><p> In some embodiments, the invention is a step of providing a nanopore array comprising: (a) a first aspect, a second aspect, and a solid phase membrane having multiple apertures passing through them. Thus, the solid phase membrane separates the first and second chambers, whereby each aperture provides fluid communication between the first chamber and the second chamber, the first of the solid phase membranes. With steps where the sides have an opaque coating on it and each aperture has a detection area extending from the opaque coating on the first side towards the second side; (b) from the first chamber through the aperture. A step of passing the polymer through a second chamber, wherein each polymer can generate a signal attached to it with at least the first wavelength indicating the properties of the polymer. And; (c) an excitation beam with a second wavelength illuminates the optical label in the detection region of the aperture from the second side of the solid phase membrane, thereby causing the optical label in the detection region to have its first wavelength. A method of determining the properties of a polymer, including the step of generating a signal different from the second wavelength; (d) the step of detecting a signal from an optical label in the detection region and determining the properties of the polymer. Is targeted.</p><p> In another embodiment, the invention is a step of providing a nanopore array comprising: (a) a first aspect, a second aspect, and a solid phase membrane having multiple apertures passing through them. The phase membrane separates the first and second chambers so that each aperture provides fluid communication between the first chamber and the second chamber, the second aspect of the solid phase membrane being its. With a step having an opaque coating on top and each aperture having a detection area extending into the second chamber from the opaque coating on the second side; (b) from the first chamber to the second chamber through the aperture. With the step of passing the polymer through, each polymer having one or more optical labels attached to it capable of generating a signal having at least a first wavelength indicating the properties of the polymer. (C) An excitation beam with a second wavelength illuminates the optical label in the detection region of the aperture from the second side of the solid phase membrane, whereby the optical label in the detection region has its first wavelength second. The subject is a method of determining the properties of a polymer, including the steps of generating a signal different from the wavelength and (d) the step of detecting a signal from an optical label in the detection region and determining the properties of the polymer. ..</p><p> In yet another embodiment, the invention provides a nanopore array comprising (a) a solid phase membrane and an opaque layer having the same spread, wherein the nanopore array has multiple apertures. Containing, separating the first chamber and the second chamber, each aperture provides fluid communication between the first chamber and the second chamber, has a signal generation region, and the opaque layer is light. A step that substantially prevents the nucleotide from passing through the nanopore array; (b) a step that allows the polynucleotide to pass from the first chamber to the second chamber through the aperture, where different types of nucleotides of the polynucleotide are. Labeled with different fluorescent labels that generate distinctive fluorescent signals, each of the apertures constrains the nucleotides of the polynucleotide and passes through the signaling region in a row; (c) with an excitation beam of the polynucleotide. The steps of exciting the fluorescence labels as they pass through the signal generation region of the aperture; (d) the step of detecting the fluorescence signal from the fluorescence label in the signal generation region and determining the properties of the polymer. (E) The subject is a method of sequencing a polynucleotide, comprising the step of sequencing a nucleotide from a fluorescent signal detected in the signal generation region of each aperture.</p><p> The present invention advantageously overcomes the problem of optical noise caused by direct lighting systems in optics-based nanopore analysis. These and other advantages of the invention are illustrated in some implementations and applications, some of which are summarized below and throughout the specification.<u style="single">In the embodiment of the present invention, for example, the following items are provided.</u><u style="single">(Item 1)</u><u style="single"> A method of determining the properties of a polymer,</u><u style="single"> A step of providing a nanopore array comprising a solid phase membrane and an opaque layer having the same spread as the nanopore array, wherein the nanopore array contains a plurality of apertures, and the first chamber and the second chamber are separated from each other. The aperture provides fluid communication between the first chamber and the second chamber, has a signal generation region, and the opaque layer substantially prevents light from passing through the nanopore array. With steps;</u><u style="single"> In the step of passing a polymer from the first chamber through the aperture to the second chamber, each polymer attaches to it an optical signal having at least a first wavelength characteristic of the polymer. With a step having one or more optical labels that can be generated;</u><u style="single"> A step of exciting the optical label of the polymer with an excitation beam having a second wavelength as they pass through the signal generation region of the aperture, wherein the optical label in the detection region is the first. With the step of generating an optical signal in which the wavelength of 1 is different from the second wavelength;</u><u style="single"> A step of detecting an optical signal from the optical label in the signal generation region and a step of determining the characteristics of the polymer.</u><u style="single">How to include.</u><u style="single">(Item 2)</u><u style="single"> The method according to item 1, wherein the opaque layer is a metal layer.</u><u style="single">(Item 3)</u><u style="single"> The method of item 2, wherein the metal layer comprises a metal selected from the group consisting of Al, Au, Ag and Cu.</u><u style="single">(Item 4)</u><u style="single"> The method of item 1, wherein the polymer is a polynucleotide and the property is its nucleotide sequence.</u><u style="single">(Item 5)</u><u style="single"> The method according to item 4, wherein the optical label is a fluorescent label and the optical signal is a fluorescent signal.</u><u style="single">(Item 6)</u><u style="single"> 5. The method of item 5, wherein each of the signal generating regions of the aperture extends from the surface of the opaque layer closest to the second chamber to the second chamber.</u><u style="single">(Item 7)</u><u style="single"> Different types of nucleotides of the polynucleotide are labeled with different fluorescent labels that generate distinctive fluorescent signals, each of the apertures constraining the nucleotides of the polynucleotide and passing through the signal generation region in a row. The method described in item 6.</u><u style="single">(Item 8)</u><u style="single"> 7. The method of item 7, further comprising a step of quenching the fluorescent signal from the excited fluorescent label outside the signal generation region using a non-fluorescent quencher.</u><u style="single">(Item 9)</u><u style="single"> 8. The method of item 8, wherein the quencher binds to the polynucleotide.</u><u style="single">(Item 10)</u><u style="single"> 9. The method of item 9, wherein the quencher is placed in the second chamber.</u><u style="single">(Item 11)</u><u style="single"> 5. The method of item 5, further comprising extinguishing the fluorescent signal from the excited fluorescent label outside the signal generation region by selecting the fluorescent label to be mutually self-quenching.</u><u style="single">(Item 12)</u><u style="single"> The method of item 1, wherein the excitation beam is directed at the nanopore array through the second chamber, whereby the opaque layer substantially prevents the excitation of the optical label in the first chamber.</u><u style="single">(Item 13)</u><u style="single"> The method of item 1, wherein each of the apertures of the nanopore array comprises a protein nanopore immobilized therein.</u><u style="single">(Item 14)</u><u style="single"> The method of item 1, wherein the optical label is an acceptor label and the excitation beam excites a donor label that excites the acceptor label as they pass through the signal generation region at each of the apertures.</u><u style="single">(Item 15)</u><u style="single"> A method of sequencing polynucleotides,</u><u style="single"> A step of providing a nanopore array comprising a solid phase membrane and an opaque layer having the same spread as the nanopore array, wherein the nanopore array contains a plurality of apertures, and the first chamber and the second chamber are separated from each other. The aperture provides fluid communication between the first chamber and the second chamber, has a signal generation region, and the opaque layer substantially prevents light from passing through the nanopore array. With steps;</u><u style="single"> In the step of passing a polynucleotide from the first chamber through the aperture to the second chamber, different types of nucleotides in the polynucleotide are labeled with different fluorescent labels that generate distinctive fluorescent signals. , Each of the apertures constrains the nucleotides of the polynucleotide and passes through the signaling region in a row;</u><u style="single"> With an excitation beam, the fluorescent label of the polynucleotide is excited as they pass through the signal generation region of the aperture;</u><u style="single"> A step of detecting a fluorescent signal from the fluorescent label in the signal generation region and a step of determining the characteristics of the polymer;</u><u style="single"> With the step of determining the sequence of nucleotides from the fluorescent signal detected in the signal generation region of each aperture.</u><u style="single">How to include.</u><u style="single">(Item 16)</u><u style="single"> The method according to item 15, wherein the opaque layer is a metal layer.</u><u style="single">(Item 17)</u><u style="single"> 16. The method of item 16, wherein the metal layer comprises an aluminum layer or a gold layer.</u><u style="single">(Item 18)</u><u style="single"> 16. The method of item 16, wherein each of the signal generating regions of the aperture extends from the surface of the metal layer closest to the second chamber to the second chamber.</u><u style="single">(Item 19)</u><u style="single"> 16. The method of item 16, wherein the excitation beam is directed at the nanopore array through the second chamber, whereby the metal layer substantially prevents excitation of the optical label in the first chamber.</u><u style="single">(Item 20)</u><u style="single"> 16. The method of item 16, further comprising the step of quenching the fluorescent signal from the excited fluorescent label outside the signal generation region using a non-fluorescent quencher.</u><u style="single">(Item 21)</u><u style="single"> 20. The method of item 20, wherein the quencher binds to the polynucleotide.</u><u style="single">(Item 22)</u><u style="single"> 21. The method of item 21, wherein the quencher is placed in the second chamber.</u><u style="single">(Item 23)</u><u style="single"> 16. The method of item 16, further comprising extinguishing the fluorescent signal from the excited fluorescent label outside the signal generation region by selecting the fluorescent label to be mutually self-quenching.</u><u style="single">(Item 24)</u><u style="single"> 16. The method of item 16, wherein the steps of excitation and detection are performed with an epi-illumination system.</u><u style="single">(Item 25)</u><u style="single"> The method of item 16, wherein each of the apertures of the nanopore array comprises a protein nanopore immobilized therein.</u><u style="single">(Item 26)</u><u style="single"> 25. The method of item 25, wherein each of the protein nanopores is immobilized on a lipid bilayer disposed across the aperture.</u><u style="single">(Item 27)</u><u style="single"> Item 16 where the fluorescent label is an acceptor label, the excitation beam excites a donor label at each of the apertures, and the donor label excites the acceptor label as they pass through the signal generation region. The method described in.</u></p>
<figref num="1A">FIGS. 1A-1H show the elements of the invention in a particular embodiment.</figref><figref num="1B">FIGS. 1A-1H show the elements of the invention in a particular embodiment.</figref><figref num="1C">FIGS. 1A-1H show the elements of the invention in a particular embodiment.</figref><figref num="1DE">FIGS. 1A-1H show the elements of the invention in a particular embodiment.</figref><figref num="1F">FIGS. 1A-1H show the elements of the invention in a particular embodiment.</figref><figref num="1G">FIGS. 1A-1H show the elements of the invention in a particular embodiment.</figref><figref num="1H">FIGS. 1A-1H show the elements of the invention in a particular embodiment.</figref>
<figref num="2">FIGS. 2A to 2B show an embodiment in which a porous layer is used as an opaque layer.</figref>
<figref num="3">Figure 3 shows the basic components of a confocal epi-illumination system.</figref>
<figref num="4A">FIGS. 4A-4C show the application of nanopore arrays with opaque layers to optical-based nanopore sequencing methods using quenching.</figref><figref num="4B">FIGS. 4A-4C show the application of nanopore arrays with opaque layers to optical-based nanopore sequencing methods using quenching.</figref><figref num="4C">FIGS. 4A-4C show the application of nanopore arrays with opaque layers to optical-based nanopore sequencing methods using quenching.</figref>
(Detailed Description of the Invention) The present invention is subject to various modifications and alternatives, the details of which are shown in the drawings as examples and will be described in more detail. However, it should be understood that the present invention is not intended to be limited to the particular embodiments described. On the contrary, it includes all modifications, equivalents, and alternatives that fall within the spirit and scope of the invention. For example, a particular nanopore type and number, a particular label, a FRET pair, a detection scheme, and a fabrication method of the invention are shown for illustrative purposes. However, the present disclosure is not limited to this, as other types of nanopores, arrays of nanopores, and other fabrication techniques can be utilized to implement various aspects of the system discussed herein. You should understand that. Guidance on aspects of the invention is incorporated herein by reference, eg, Cao, Nanostructures & Nanomaterials (Imperial College Press, 2004); Levinson, Principles of Lithography, Second Edition (SPIE). Press, 2005); Doering and Nishi, Editors, Handbook of Semiconductor Manufacturing Technology, Second Edition (CRC Press, 2007); Sawyer et al, Electrochemistry for Chemists, 2<sup>nd </sup>edition (Wiley Interscience, 1995); Bard and Faulkner, Electrochemical Methods: Fundamentals and Applications, 2<sup>nd </sup>edition (Wiley, 2000); Lakowicz, Principles of Fluorescence Spectroscopy, 3<sup>rd</sup> It is found in many available references and articles well known to those of skill in the art, including edition (Springer, 2006); Hermanson, Bioconjugate Techniques, Second Edition (Academic Press, 2008) ;.
The present invention is directed to methods and devices for optical-based nanopore analysis of molecules such as nucleic acids, including nanopore arrays having one or more light shielding layers, i.e., one or more opaque layers. Typically, nanopore arrays are manufactured as thin sheets of materials such as silicon, silicon nitride, silicon oxide, aluminum oxide, etc., which easily transmit light at thicknesses specifically used, such as less than 50-100 nm. This is not a problem for the electrical detection of the analyte. However, in optical-based detection of labeled molecules passing through nanopores, the light transmitted through the array always excites the material outside the intended reaction site, the signal-generating region, thereby, for example, non-specificity. Generates optical noise such as background fluorescence and fluorescence from labels of molecules that have not yet entered the nanopore. In one aspect, the invention provides a nanopore array with one or more light shielding layers that reflect and / or absorb light from an excitation beam, thereby at the intended reaction site associated with the nanopores of the array. This problem is addressed by reducing the background noise to the resulting optical signal. In some embodiments, this allows direct illumination to excite the optical label at the intended reaction site (such as the detection zone or signal generation zone described more completely below). In some embodiments, the opaque layer may be a metal layer. Such a metal layer may include Sn, Al, V, Ti, Ni, Mo, Ta, W, Au, Ag or Cu. In some embodiments, such metal layers may contain Al, Au, Ag or Cu. In yet other embodiments, such metal layers may contain aluminum or gold, or may contain only aluminum. The thickness of the opaque layer may vary widely, depending on the physical and chemical properties of the materials that make up the layer. In some embodiments, the thickness of the opaque layer may be at least 5 nm, or at least 10 nm, or at least 40 nm. In other embodiments, it is opaque. The thickness of the bright layer may be in the range of 5 to 100 nm, and in other embodiments, the thickness of the opaque layer may be in the range of 10 to 80 nm. The opaque layer does not need to shield (ie reflect or absorb) 100% of the light from the excitation beam. In some embodiments, the opaque layer may shield incident light from the excitation beam by at least 10 percent, and in other embodiments, the opaque layer may shield incident light from the excitation beam by at least 50 percent. ..
FIG. 1A shows the above aspect of the invention for a particular embodiment. The solid-state membrane (100) has an opaque coating (102) on the first side surface (104), a surface (105) facing the first chamber (112) and a second chamber. It forms a laminated film (101) having a second side surface (106) facing (114). The laminated membrane (101) separates the first chamber (112) from the second chamber (114), each providing fluid communication between the first chamber (112) and the second chamber (114). Includes an array of apertures (110). The aperture (110) may be a solid state or synthetic nanopore, may be used directly, or may be used to immobilize a protein nanopore through which passage occurs. In general, apertures have diameters or cross-sectional dimensions that are smaller than the wavelength of the excitation beam, so that light from such beams is not transmitted through the aperture. In some embodiments, the aperture has a diameter of 100 nm or less. In some embodiments, the diameter of the circular aperture is 0.586 times or less than the wavelength of the excitation beam.
In some embodiments of the preceding paragraph, the method of the invention comprises the following steps: (a) a nanopore array comprising a solid phase film having a first aspect, a second aspect, and multiple apertures passing through them. A solid phase membrane separates the first and second chambers, whereby each aperture provides fluid communication between the first and second chambers and is solid. With a step where the first side of the phase membrane has an opaque coating on it, and each aperture has a detection area extending from the opaque coating on the first side towards the second side; (b) aperture. Through the step of passing the polymer from the first chamber to the second chamber through, each polymer can generate a signal attached to it with at least the first wavelength demonstrating the properties of the polymer 1 Steps with one or more optical labels; (c) Illuminate the optical label in the detection region of the aperture from the second side of the solid phase film with an excitation beam with a second wavelength, thereby illuminating the optical label in the detection region. Can be carried out by a step of generating a signal whose first wavelength is different from that of the second wavelength; (d) a step of detecting a signal from an optical label in the detection region and determining the properties of the polymer. ..
In another embodiment, as illustrated in FIG. 1C, the method of the invention comprises the following steps: (a) a solid phase membrane having a first aspect, a second aspect, and multiple apertures through them. A solid phase membrane separates the first and second chambers, whereby each aperture provides fluid communication between the first and second chambers. Provided with a step where the second side of the solid phase film has an opaque coating on it and each aperture has a detection area extending into the second chamber from the opaque coating on the second side; b) The step of passing the polymer from the first chamber to the second chamber through the aperture, where each polymer generates a signal attached to it that has at least the first wavelength characteristic of the polymer. With one or more optical labels that can be; (c) an excitation beam with a second wavelength illuminates the optical label in the detection region of the aperture from the second side of the solid phase membrane, thereby the detection region. The optical label in is a step of generating a signal whose first wavelength is different from that of the second wavelength; (d) a step of detecting a signal from the optical label in the detection region and determining the properties of the polymer. Can be carried out.
In some embodiments, whenever the opaque coating or opaque layer is metal, the nearest neighbor nanopore distance and excitation beam wavelength are selected to minimize plasmon-mediated anomalous transmission through the nanopore array. Guidance for such selection is disclosed in the following references incorporated by reference: Ebbesen et al., Nature, 391: 667-669 (1998); Ebbesen et al., U.S. Pat. No. 5,973,316; Ibid., No. 6040936; 6236033; 6856715; 7057151; 7248756; 8174696; Gur et al., Optics Comm., 284: 3509-3517 (2011); Ghaemi et al., Physical Review B, 58: 6779-6782 (1998); Pacifici et al., Optics Express, 16 (12): 9222-9238 (2008); etc. In some embodiments, the nearest nanopore distance (eg, the nearest nearest nanopore distance expected in a random (eg, Poisson distribution) array of nanopores) is selected to be approximately equal to, for example, the excitation wavelength for exciting the optical label. Will be done.
In some embodiments, the signaling region (116) (or equivalent intended reaction site) is located within the nanopore and immediately adjacent to the exit of the nanopore on the second aspect (106), respectively. Including, such regions do not overlap with the equivalent regions of other nanopores. In some embodiments, a labeled molecule, such as a labeled nucleic acid molecule, is loaded into or placed in a first chamber (112), either directly or via an inserted protein nanopore. Then, it passes from the first chamber (112) to the second chamber (114) through the aperture of the laminated film (101). As labeled molecules pass through the aperture (110) and / or exit the aperture (110), these molecules can be directly illuminated by the excitation beam (118). The excitation beam (118) can be selected or configured to directly excite the labeled molecule or indirectly excite the labeled molecule via FRET interaction. In some embodiments (FIG. 1B), the signal generation region (120) (or equivalent intended reaction site) is the interior of the nanopore from the first aspect (104) to the second aspect (106), respectively. And the region immediately adjacent to the exit of the nanopore on the second aspect (106), such region does not overlap with the equivalent region of the other aperture (or nanopore). In yet another embodiment, the signal generation regions (or intended reaction sites) are inside the nanopore from its inlet in the first chamber to its exit in the second chamber and immediately adjacent to the inlet and outlet of the nanopore, respectively. Containing regions adjacent to, such regions do not overlap with equivalent regions of other apertures.
As mentioned above, the aperture of the laminated film of the present invention may be used directly as nanopores or may be used to retain or immobilize one or more protein nanopores. In some embodiments of the latter type, one or more protein nanopores may be placed on the surface of the opaque layer (eg 105 in FIGS. 1A, 1B, or 1E) or on the second side of the laminated membrane (eg FIG. 1D). It may be embedded in a lipid bilayer placed on any of the surfaces of 106). Figures 1D and 1E show a lipid bilayer (126), which is shown above the surface (106) of Figure 1D and the surface (105) of Figure 1E), as well as an opaque layer or coating (102), solid state. A cross section of a laminated film (101) having a film (100) and an aperture (110) is shown. In the particular embodiment shown, a protein nanopore (122) attached with a label (124) (eg, a donor label such as a quantum dot, metal nanoparticles, or other fluorescent nanoparticles to generate a FRET signal). Is shown inserted into the lipid bilayer (126), but as noted elsewhere, the invention includes protein nanoparticles with unlabeled configurations for the generation of FRET signals. In some embodiments of FIG. 1D having a signal generation region adjacent to the label (124) (ie, within the FRET distance of the label (124)), the signal generation region is from the first side surface (104) to the second side surface. It corresponds to the configuration shown in FIG. 1B which extends to the space close to the aperture or the exit of the nanopore in (106). Similarly, in some embodiments of FIG. 1E, which also have a signal generation region adjacent to the label (124) (eg, within the FRET distance of the label (124)), the signal generation region is second from the surface (105). Corresponds to the configuration shown in FIG. 1A, which extends to the space close to the aperture or nanopore exit on the side surface (106) of.
In some embodiments as shown in FIGS. 1A-1E, the laminated film may further include an immobilizing coating such as an oxide coating such as a silicon oxide coating in order to stabilize the metal layer. For example, a physical or chemical deposition technique is used to coat a silicon nitride film with an opaque material such as metal to form a laminated film, and then the aperture is etched or perforated using focused electrons or ion beams. An array of apertures may be formed on the laminated film. Such arrays may then be further coated with a protective layer such as silicon oxide again using chemical arrangements or vapor deposition techniques.
In some embodiments, the invention is a step of providing a nanopore array comprising: (a) a first aspect, a second aspect, and a solid phase membrane having multiple apertures passing through them. Thus, the solid phase membrane separates the first and second chambers, whereby each aperture provides fluid communication between the first chamber and the second chamber, the first of the solid phase membranes. With steps where the sides have an opaque coating on it and each aperture has a detection area extending from the opaque coating on the first side towards the second side; (b) from the first chamber through the aperture. A step of passing the polymer through a second chamber, wherein each polymer can generate a signal attached to it with at least the first wavelength indicating the properties of the polymer. And; (c) illuminate the optical label in the detection region of the aperture from the second side of the solid phase membrane with an excitation beam containing at least the second wavelength, whereby the optical label in the detection region is its first. Biology containing nucleic acids and proteins by the steps of generating a signal whose wavelength differs from that of the second wavelength; (d) the step of detecting the signal from the optical label in the detection region and determining the properties of the polymer. It may include methods for characterizing a polymer, such as an optical polymer. In some embodiments, the polymer may be a polynucleotide or protein. In yet other embodiments, the polymer may be a polynucleotide. In a further embodiment, the polynucleotide may be a single-stranded nucleic acid. In some embodiments, the characteristic of the polymer analyzed or determined is the monomer sequence of the polymer, such as a nucleotide sequence. In some embodiments, the optical label on the polymer is a US patent and patent and international publication incorporated herein by reference: No. 8,771,491; No. 2013/0203050; Or a FRET label as described in WO 2014/190322. In some embodiments, the aperture comprises a protein nanopore. Simply put, in some embodiments, the FRET label comprises at least one FRET donor label and at least one FRET acceptor label in each signal generation region, and the excitation beam excites the FRET donor label, which in turn is the donor label. Transfers energy to the FRET acceptor label within the FRET distance of, which in turn emits an optical signal. Typically, the excitation beam contains a second wavelength and the optical signal contains a first wavelength that is different from the second wavelength, allowing the use of, for example, epi-illumination systems. In some embodiments, the detection area extends from the opaque coating on the first side to the second side and includes an adjacent extramembrane space in the immediate vicinity of the aperture and / or the exit of the nanopore. In some embodiments, such extramembrane space does not extend beyond 50 nm from the exit of the nanopore or aperture. In other embodiments, such extramembrane space does not extend beyond 10 nm from the exit of the nanopore or aperture. Does not extend beyond 50 nm. In other embodiments, such extramembrane space does not extend beyond 10 nm from the exit of the nanopore or aperture. Does not extend beyond 50 nm. In other embodiments, such extramembrane space does not extend beyond 10 nm from the exit of the nanopore or aperture.
Simply put, apertures and / or nanopores are labeled with one or more FRET donors and polymers are FRETs, respectively, as described more fully in US Pat. No. 8,771,491. Labeled with an acceptor, thereby at least the selected donor and acceptor form a FRET pair, i.e. the donor's emission spectrum overlaps with the absorption spectrum of at least one acceptor, thereby meeting other conditions (eg, donor). Excitation, donor and acceptor are within FRET distance, donor and acceptor are in proper relative orientation, etc.), FRET interaction can occur. In the FRET interaction, the donor's excitation energy is non-radiatively transferred to the acceptor, after which the acceptor emits an optical signal with an energy lower than the donor's excitation energy. Donors are usually excited by illuminating a beam of light, such as that produced by a laser.
In some embodiments, as described in Huber et al., US Patent Publication No. 2013/0203050, which is incorporated herein by reference, protein nanopores can be applied without a lipid bilayer or with only a small amount of lipid bilayer. At the same time, it may be inserted into a membrane in a solid state to form an array. The composition of such protein nanopores / apertures is shown in Figure 1F. In this particular embodiment, the laminated film (101) comprising a solid state film (100) and an opaque layer (102) is labeled with a donor (128), which may be optically active particles such as quantum dots. The protein nanopore (122) contains an immobilized aperture (107). As the acceptor-labeled polymer (130) exits through the bore of the protein nanopore (122), the acceptor label passes through the FRET distance of the donor (128). The size of the aperture (107) is designed to allow immobilization of a single protein nanopore. Direct illumination of the aperture (107) with the excitation beam (133) excites the donor (128) and enters the FRET interaction with the acceptor of the labeled polymer (130) passing through the protein nanopore (122). Will be possible. The opaque layer (102), on the other hand, reduces the emission of the beam (133) that illuminates the acceptor above the labeled polymer (131) on the opposite side of the opaque layer (102) as the beam (133). The opaque layer (102) shields radiation from the beam (133) by absorbing (135) and / or reflecting (137) the beam (133).
Figure 1G shows a further embodiment. Here, the surface of the opaque layer (102), such as the metal layer, forms the boundary of the second chamber (114). In some embodiments, an array of solid state apertures (146) can be manufactured using conventional micromachine techniques. For example, a non-conducting solid state film (100) such as a silicon nitride layer is added to a silicon substrate (140) by a method such as a chemical vapor deposition method. In some embodiments, the layer (100) is in the range of 30-100 nm. An opaque layer (102) such as a metal layer is added on the layer (100) by a method such as a chemical vapor deposition method to form a three-layer sheet. A layer of photoresist may be added to the opaque layer (102), after which the photoresist material is developed at the aperture position and etched through the opaque layer (102) and the solid state film (100). A hole is formed and a portion of the aperture (146) is formed. A second etching is performed through the silicon layer (140) to form the remaining aperture (146) in the array. The nanopore sensing device according to one embodiment of the invention is a lipid bilayer on the surface (141) of an opaque layer (102) into which at least one protein nanopore (122) with a FRET donor label (124) has been inserted. It can be constructed by depositing (126). When placed in the first chamber (112), the charged and labeled polymer (150), including, for example, the acceptor labels (151) and (152) for two different types of monomers, is each acceptor label. It can pass through the protein nanopores (122) that constrain (151 or 152) and come within the FRET distance (142) of the donor label (124). The donor label (124) is excited by the beam (133) and transfers excitation energy to the acceptor label within the FRET distance (142), which in turn emits a FRET signal (144) indicating the monomer to which the label is attached. do.
In yet another embodiment, as shown in FIG. 1H, a lipid bilayer (126) is placed on the surface (104) of the layer (100), thereby facing the side surface to which the excitation beam (133) is directed. A protein nanopore (122) is inserted on the side surface of the membrane (101).
In some embodiments, the opaque layer may include an opaque porous layer, which in some embodiments may be an opaque nanoporous layer, as shown in FIGS. 2A and 2B. In such an embodiment, the laminated film (101) is a nanometer-sized hole that provides an indirect and / or snake-like passage across the solid state film (200) and the layer of the aperture (204). Includes a nanoporous layer (202) containing an opaque material having. FIG. 2B shows an embodiment comprising a labeled protein nanopore (210) inserted into a lipid bilayer (206) located on the second aspect (216) of a solid state membrane (200). .. Similar to the embodiments of FIGS. 1A-1H, the nanoporous layer (202) emits radiation directed at the second side surface (216) of the solid state membrane (200) to the other nanoporous layer (202). Shields or reduces access to labeled polymers or other materials on the flanks, thereby reducing the generation of unwanted noise in the optical signal from detection events at the exit of the protein nanopore (210).
As mentioned above, in some embodiments, an epi-illumination system in which the delivery of an excitation beam and the collection of optical signals occur through a single objective lens to directly illuminate a marker on a polymer analyte or a donor on a nanopore. Is used. Figure 3 shows the basic components of the confocal epi-illumination system used in the present invention. The excitation beam (302) passes through the bicolor mirror (304) toward the objective lens (306), and the objective lens (306) concentrates the excitation beam (302) on the laminated film (300) (310). In it, the label is directly excited to emit an optical signal such as a fluorescent signal, or indirectly excited via a FRET interaction to emit an optical signal. Such an optical signal is collected by the objective lens (306) and directed at a dichroic mirror (304) selected to pass the light of the excitation beam (302) but reflect the light of the optical signal (311). Be done. The reflected optical signal (311) passes through a lens (314) that concentrates the optical signal (311) through a pinhole (316) to the detector (318).
In some embodiments, the device for performing the above method for polymers containing single-stranded nucleic acids typically comprises a set of electrodes to establish an electric field across the laminated membrane and nanopores. include. Single-stranded nucleic acids are exposed to nanopores by placing them in an electrolyte in a first chamber configured as the "cis" side of the laminated membrane by placing a cathode in the chamber. When an electric field is applied, the negatively charged single-stranded nucleic acid is captured by the nanopores and placed in the chamber to place an anode in the second chamber on the other side of the laminated membrane, which is configured as the "trans" side of the membrane. pass. The speed of passage depends in part on the ionic strength of the electrolyte in the first and second chambers as well as the voltage applied across the nanopores. In optical-based detection, the pass rate can be selected, for example, by preliminary calibration measurements using predetermined standards of labeled single-stranded nucleic acids that generate signals at different rates expected per nanopore at different voltages. .. Therefore, for DNA sequencing applications, transit rates can be selected based on signal rates from such calibration measurements. Thus, from such measurements, the voltage at which reliable nucleotide identification is possible or maximum, eg, across an array of nanopores, can be selected. In some embodiments, such calibration can be performed using nucleic acids from the sample of the template being analyzed (instead of or in addition to a given standard sequence). In some embodiments, such calibration may be performed in real time during the sequencing run, and the applied voltage is, for example, real time based on such measurements to maximize the acquisition of nucleotide-specific signals. It may be modified with. Nanopores and Nanopore Arrays
As mentioned above, the nanopores used in the present invention are solid nanopores, protein nanopores, or hybrid nanopores containing protein nanopores or organic nanotubes, such as carbon or graphene nanotubes composed of solid membranes or similar frameworks. There may be. An important feature of nanopores is that they constrain polymer analytes such as polynucleotides, whereby their monomers pass through detection zones (or signaling regions) in sequence (ie, nucleotides pass through detection zones one at a time, or one at a time. Passing in a row) is included. In some embodiments, additional features of nanopores include passing single-stranded nucleic acids without passing through double-stranded nucleic acids or equivalent bulky molecules.
In some embodiments, the nanopores used in conjunction with the methods and devices of the invention are provided in the form of an array, such as an array of clusters of nanopores that can be regularly arranged in a plane. In some embodiments, the clusters are within separate resolution limit areas, but from the nanopores within the same cluster, so that the optical signals from the nanopores of different clusters can be distinguished by the optical detection system used. The optical signal does not necessarily have to be able to be assigned to a particular nanopore within such a cluster by the optical detection system used.
Nanopores in the solid state are silicon nitride (Si)<sub>3</sub>N<sub>4</sub>) And silicon dioxide (SiO)<sub>2</sub>) Etc., but are not limited to these. Manufacture and operation of nanopores for application examples of analysis such as DNA sequencing are disclosed in the following exemplary references incorporated by reference: Ling, US Pat. No. 7,678,562; Hu et al, US Pat. No. 7,397,232. No.; Golovchenko et al, US Pat. No. 6,464,842; Chu et al, US Pat. No. 5,798,042; Sauer et al, US Pat. No. 7,001,792; Su et al, US Pat. No. 7,744,816; Church et al, US Pat. No. 5,795,782 No.; Bayley et al, US Pat. No. 6,426,231; Akeson et al, US Pat. No. 7,189,503; Bayley et al, US Pat. No. 6,916,665; Akeson et al, US Pat. No. 6,267,872; 2009/0029477; Howorka et al, International Patent Publication WO2009 / 007743; Brown et al, International Patent Publication WO2011 / 067559; Meller et al, International Patent Publication WO2009 / 020682; Polonsky et al, International Patent Publication WO2008 / 092760; Van der Zaag et al, International Patent Published WO2010 / 007537; Yan et al, Nano Letters, 5 (6): 1129-1134 (2005); Iqbal et al, NatureNanotechnology, 2: 243-248 (2007); Wanunu et al, Nano Letters, 7 (6) : 1580-1585 (2007); Dekker, Nature Nanotechnology, 2: 209-215 (2007); Storm et al, Nature Materials, 2: 537-540 (2003); Wu et al, Electrophoresis, 29 (13): 2754-2759 (2008); Nakane et al, Electrophoresis, 23: 2592-2601 (2002); Zhe et al, J. Micromech. Microeng., 17: 304-313 (2007); Henriquez et al, The Analyst, 129: 478-482 (2004); Jagtiani et al , J.Micromech.Microeng., 16: 1530-1539 (2006); Nakane et al, J.Phys.Condens.Matter, 15 R1365-R1393 (2003); DeBlois et al, Rev.Sci.Instruments, 41 (7) ): 909-916 (1970); Clarke et al, Nature Nanotechnology, 4 (4): 265-270 (2009); Bayley et al, US Patent Publication No. 2003/0215881; etc.
In some embodiments, the invention comprises a nanopore array having one or more light shielding layers, i.e., one or more opaque layers. Typically, nanopore arrays are manufactured as thin sheets of materials such as silicon, silicon nitride, silicon oxide, aluminum oxide, etc., which easily transmit light at thicknesses specifically used, such as less than 50-100 nm. This is not a problem for the electrical detection of the analyte. However, in the optical-based detection of labeled molecules passing through the nanopores, the light transmitted through the array always excites the material outside the intended reaction site, thereby, for example, non-specific background fluorescence, Generates optical noise such as fluorescence from the labels of molecules that have not yet entered the nanopores. In one aspect, the invention provides a nanopore array with one or more light shielding layers that reflect and / or absorb light from an excitation beam, thereby at the intended reaction site associated with the nanopores of the array. This problem is addressed by reducing the background noise to the resulting optical signal. In some embodiments, this allows the optical label at the intended reaction site to be excited by direct illumination. In some embodiments, the opaque layer may be a metal layer. Such a metal layer may include Sn, Al, V, Ti, Ni, Mo, Ta, W, Au, Ag or Cu. In some embodiments, such metal layers may contain Al, Au, Ag or Cu. In yet other embodiments, such metal layers may contain aluminum or gold, or may contain only aluminum. The thickness of the opaque layer may vary widely, depending on the physical and chemical properties of the materials that make up the layer. In some embodiments, the thickness of the opaque layer may be at least 5 nm, or at least 10 nm, or at least 40 nm. In other embodiments, the thickness of the opaque layer may be in the range of 5-100 nm, and in other embodiments, the thickness of the opaque layer may be in the range of 10-80 nm. The opaque layer emits light from the excitation beam It does not need to be 100% shielded (ie reflected or absorbed). In some embodiments, the opaque layer may shield incident light from the excitation beam by at least 10 percent, and in other embodiments, the opaque layer may shield incident light from the excitation beam by at least 50 percent. ..
The opaque layer or coating can be made on a solid film by various techniques known in the art. Physical vapor deposition methods such as chemical vapor deposition, electrodeposition, epitaxy, thermal oxidation, evaporation and sputtering, and material deposition techniques such as casting can be used. In some embodiments, atomic layer deposition can be used. For example, US Pat. No. 6,464,842 incorporated by reference; Wei et al., Small, Vol. 6 (13), pp. 1406-1414 (2010).
In some embodiments, channels or apertures of 1-100 nm may be formed through a solid substrate, usually a planar substrate, eg, a membrane, through which the analyte, such as single-stranded DNA, migrates. Induced to do. In another embodiment a channel or aperture of 2-50 nm is formed through the substrate, and in yet another embodiment 2-30 nm, or 2-20 nm, or 3-30 nm, or 3-20 nm, or 3 A channel or aperture of ~ 10 nm is formed through the substrate. The solid-state approach to producing nanopores provides robustness and durability while at the same time being able to adjust the size and shape of nanopores, to produce high density arrays of nanopores on a wafer scale, and to be superior to lipid-based systems. It offers mechanical, chemical and thermal properties, as well as the possibility of integrating with electronic or optical readout techniques. Biological nanopores, on the other hand, are physical and / or chemical nanopores by means of reproducible narrow bores or cavities, especially those in the range of 1-10 nanometers, and methods of designing and manufacturing conventional proteins. Provides techniques for adjusting properties and for directly or indirectly attaching groups or elements such as fluorescent labels that may be FRET donors or acceptors. Protein nanopores typically rely on a delicate lipid bilayer for mechanical supports, and the production of solid-state nanopores with precise dimensions remains difficult. In some embodiments, solid-state nanopores are combined with biological nanopores to form so-called "hybrid" nanopores, which overcome some of these shortcomings and in doing so solid-state. It provides the precision of biological pore proteins for the stability of nanopores. In optical readout techniques, hybrid nanopores provide a precise location for the nanopores, which greatly simplifies data acquisition.
In some embodiments, clusters may be formed by placing protein nanopores within a lipid bilayer supported by a solid phase membrane containing an array of apertures. For example, such an array may include apertures made into solid phase supports (eg, pierced or etched). The geometry of such apertures may vary depending on the fabrication technique used. In some embodiments, each of such apertures is associated with or included in a separate resolution limit zone; however, in other embodiments, multiple apertures may be within the same resolution limit zone. The cross-sectional area of the aperture may vary widely and may or may not be the same between different clusters, but such areas are usually substantially the same as the result of conventional fabrication techniques. In some embodiments, the aperture has a minimum line dimension in the range of 10 to 200 nm (eg, diameter in the case of a circular aperture), or about 100 to 3 × 10.<sup>4</sup>nm<sup>2</sup>Has an area in the range of. A lipid bilayer may be placed across the aperture. The distribution of protein nanopores per aperture may vary, for example by controlling the concentration of protein nanopores during the insertion step. In such an embodiment, the cluster of nanopores may contain a random number of nanopores. In some embodiments where protein nanopores are randomly inserted into apertures, clusters containing one or more apertures on average have a predetermined number of protein nanopores greater than zero; other embodiments. So, such clusters have a predetermined number of protein nanopores greater than 0.25; in other embodiments, such clusters have a predetermined number of protein nanopores greater than 0.5; other. In embodiments, such clusters have a predetermined number of protein nanopores greater than 0.75; in other embodiments, such clusters have a predetermined number of protein nanopores greater than 1.0.
In some embodiments, the methods and devices of the invention include a solid phase membrane, such as a SiN membrane, which has an array of apertures through which a first chamber and a second chamber (possibly, in some cases). A communication is provided between the "cis chamber" and the "transchamber") to support the lipid bilayer on the surface facing the second or transchamber. In some embodiments, the diameter of the aperture in such a solid phase membrane may be in the range of 10 to 200 nm or 20 to 100 nm. In some embodiments, such solid phase membranes further include protein nanopores inserted into the lipid bilayer at the region where such bilayer straddles the surface aperture facing the transchamber. In some embodiments, such protein nanopores are inserted from the cis side of the solid phase membrane using the techniques described herein. In some embodiments, such protein nanopores include a barrel or bore along the axis and have a "cap" structure at one end and a "stem" structure at the other end (Song et al., Science, Vol. 274, pp. 1859-1866 (using terminology from 1996)), which has the same or similar structure to α-hemolysin. In some embodiments using such protein nanopores, insertion into the lipid bilayer is oriented such that its cap structure is exposed towards the cis chamber and its stem structure is exposed towards the transchamber. Brings protein nanopores to
In some embodiments, the invention may use hybrid nanopores in a cluster, specifically for optical-based nanopore sequencing of polynucleotides. Such nanopores include solid-state orifices or apertures into which protein biosensors such as protein nanopores are stably inserted. The charged polymer may be attached to a protein nanopore (eg, alpha hemolysin) by conventional protein engineering techniques, after which an applied electric field is used to guide the protein nanopore into the aperture of a solid membrane. May be done. In some embodiments, the aperture on the solid substrate is chosen to be slightly smaller than the protein, which prevents the protein from migrating the aperture. Instead, the protein will be embedded in a solid orifice.
In some embodiments, the donor fluorophore is attached to the protein nanopore. The complex is then subjected to a solid state aperture or nanohole (eg, diameter 3) by applying an electric field between both ends of the solid state nanohole until the protein nanopores are transported to the solid state nanoholes to form hybrid nanopores. Insert at ~ 10nm). The formation of hybrid nanopores can be verified by (a) inserted protein nanopores, which cause a current drop due to partial blockage of solid-state nanoholes or apertures, and (b) optical detection of donor fluorophores. can.
Nanopores in solid state or synthetic can be prepared in a variety of ways as exemplified in the references cited above. In some embodiments, nanopores synthesized into a variety of materials using a helium ion microscope, eg, as disclosed in Yang et al., Nanotechnolgy, Vol. 22, pp. 285310 (2011), which is incorporated herein by reference. You may open. A thin film material processed into a free-standing membrane, such as a chip that supports one or more regions of silicon nitride, is introduced into a helium ion microscope (HIM) chamber. While setting the microscope to a low magnification, HIM motor control is used to guide the self-supporting membrane to the path of the ion beam. Beam parameters, including focus and astigmatism correction, are adjusted in the region adjacent to the free-standing membrane but on a solid substrate. After properly fixing the parameters, move the chip position so that the self-supporting membrane region is centered on the ion beam scan region and the beam is blanked. Set the HIM field of view to dimensions (in μm) sufficient to contain the entire expected nanopore pattern and to be useful for future optical readouts (ie, depending on optical magnification, camera resolution, etc.) do. The ion beam is then rasterized once across the entire field of view at pixel dwell time, resulting in a total ion dose sufficient to remove all or most of the membrane autofluorescence. The field of view is then set to the appropriate value (smaller than when used above) and a lithography-defined milling of either a single nanopore or an array of nanopores is performed. The pixel dwell time of the pattern is set to result in one or more predetermined diameter nanopores determined through the use of a calibrated sample prior to sample processing. This entire process is repeated on a single chip, each in the desired region and / or for each chip introduced into the HIM chamber.
In some embodiments, the nanopores are attached with one or more labels for use in optical-based nanopore sequencing methods. The label may be a member of a Forster resonance energy transfer (FRET) pair. Such labels may include organic fluorophores, chemical luminescence labels, quantum dots, metal nanoparticles, and / or fluorescent proteins. The target nucleic acid may have one completely different label per nucleotide. The label attached to the nucleotide may be selected from the group consisting of organic fluorophores. Label attachment sites in pore proteins can be generated by conventional protein engineering methods, for example, mutant proteins can be constructed that allow specific binding of labels. As an example, a cysteine residue may be inserted at the desired position of the protein, inserting a thiol (SH) group that can be used to attach the label. Cysteine can be replaced with naturally occurring amino acids or incorporated as additional amino acids. The maleimide activation label is then covalently attached to the thiol residue of the protein nanopore. In a preferred embodiment, attachment of the label to the protein nanopore or label on the nucleic acid is reversible. By realizing a cleavable crosslinker, an easily breakable chemical bond (eg, SS bond or pH-variable bond) is introduced and the label is removed when the applicable conditions are met. May be good. Optically based nanopore sequence determination by FRET signal
In some embodiments, the nanopores can be labeled with one or more quantum dots. In particular, in some embodiments, one or more quantum dots may be attached to the nanopores or to adjacent solid support (within the FRET distance from the inlet and outlet of the nanopores). It may be attached or used as a donor in a FRET reaction with an acceptor on the analyte. Such use of quantum dots is well known and is widely described in scientific and patent literature, such as US Pat. No. 6,252,303; 6,855,551; 7,235,361; incorporated herein by reference.
An example of a quantum dot that can be used as a pore marker is a CdTe quantum dot that can be synthesized in an aqueous solution. CdTe quantum dots may be functionalized with nucleophilic groups such as functional groups such as primary amines, thiols, or carboxylic acids. CdTe quantum dots may include a mercaptopropionic acid capping ligand having a carboxylic acid functional group that can be used to covalently link the quantum dots to the primary amine outside the protein pore. The cross-linking reaction may be accomplished using standard cross-linking reagents (homo-bifunctional as well as hetero-bifunctional) known to those skilled in the art of bioconjugation. Care may be taken to ensure that the modification does not impair or substantially impair the transfer of nucleic acid through the nanopores. This may be achieved by varying the length of the crosslinker molecules used to attach the donor label to the nanopores.
For example, carboxy-modified CdTe quantum dots using a primary amine of lysine residue 131 of a natural alpha hemolysin protein (Song, L. et al., Science 274 (1996): 1859-1866). , 1-Ethyl-3- [3-dimethylaminopropyl] carbodiimide hydrochloride / N-hydroxysulfosuccinimide (EDC / NHS) may be covalently attached via coupling chemistry. Alternatively, the amino acid 129 (threonine) may be replaced with cysteine. Since the native alpha hemolysin protein has no other cysteine residues, the thiol side group of the newly inserted cysteine may be used to covalently attach other chemical moieties.
Biological polymers such as nucleic acid molecules or polymers may be labeled with one or more acceptor labels. For nucleic acid molecules, each of the four nucleotides or the building block of the nucleic acid molecule may be labeled with an acceptor label, thereby creating a labeled (eg, fluorescent) counterpart for each of the naturally occurring nucleotides. NS. The acceptor label may be in the form of an energy accepting molecule that can be attached to one or more nucleotides on a portion of the converted nucleic acid or the entire strand.
Various methods may be utilized to label the monomers or nucleotides of nucleic acid molecules or polymers. The labeled nucleotide may be incorporated into the nucleic acid during the synthesis of the new nucleic acid using the original sample as a template ("synthetic labeling"). For example, labeling of nucleic acids may be achieved via PCR, whole genome amplification, rolling circle amplification, or primer extension, or through various combinations and extensions of the above methods known to those of skill in the art.
The label may contain a reactive group such as a nucleophile (amine, thiol, etc.). Such nucleophiles, which are not present in natural nucleic acids, can then be used to attach fluorescent labels via amine or thiol-reactive chemistries such as NHS esters, maleimides, epoxy rings, isocyanates. can. Such nucleophilic reactive fluorescent dyes (ie, NHS-dyes) are readily available from different sources. The advantage of labeling nucleic acids with small nucleophiles is that integration of such labeled nucleotides is highly efficient when the "synthetic labeling" technique is used. Highly fluorescently labeled nucleic acid building blocks can be poorly integrated into newly synthesized DNA by polymerases due to steric hindrance of the labels during the polymerization process.
Whenever two or more mutually quenching dyes are used, such dyes may be attached to the DNA using orthogonal adhesion chemistry. For example, NHS esters can be used to react very specifically with primary amines, or maleimide will react with thiol groups. Primary amine (NH)<sub>2</sub>) Or thiol (SH) modified nucleotides are commercially available. These relatively small modifications are readily incorporated into polymerase-mediated DNA synthesis and can be used in subsequent labeling reactions using either NHS or maleimide-modified dyes. Guidance for selecting and using such orthogonal linker chemistry can be found in Hermanson (supra).
Huisgen-type cycloadditions for copper-catalyzed and non-catalyzed reactions as additional orthogonal cycloadditions for typical attachment positions; eg Gutsmiedl et al., Org. Lett., Vol. 11: pp. 2405-2408 (2009). ), Alken and oxynitrile cycloadditions; eg Seelig et al., Tetrahedron Lett., Vol. 38: 7729-7732 (1997), Diels-Alder cycloadditions; eg Cassi et al., J. .Am.Chem.Soc., Vol. 134: 5887-5892 (2012); Shao et al., J.Am.Chem.Soc., Vol. 117: 3893-3899 (1995); Rideout, Science, Vol. 233 Carbonyl ligation, such as disclosed on pages 561 to 563 (1986); eg Brinkley, Bioconjugate Chemistry, Volume 3: Cycloaddition, as disclosed on pages 2 to 13 (1992); eg Schuler et al., Bioconjugate. Chemistry, Vol. 13: 1039-1043 (2002); Dawson et al., Science, Vol. 266: 776-779 (1994); the original chemical ligation disclosed; or, for example, Hermanson (supra). The formation of amides via active esters, which is carried out.
Combinations of 1, 2, 3, or 4 nucleotides in a nucleic acid chain may be exchanged for their labeled counterparts. Various combinations of labeled nucleotides can be sequenced in parallel, eg, from a source nucleic acid or DNA in a combination of two labeled nucleotides in addition to four single labeled samples. Labeling results in a total of 10 differently labeled nucleic acid molecules or DNAs (G, A, T, C, GA, GT, GC, AT, AC, TC). .. The resulting sequence pattern can allow for more accurate sequence alignment due to the overlap of nucleotide positions in the redundant sequence readout. In some embodiments, polymers such as polynucleotides or peptides are labeled with a single fluorescent label attached to a single type of monomer, eg, all T's (or substantially all) of the polynucleotide. T) is labeled with a fluorescent label, such as a cyanine dye. In such embodiments, the collection or sequence of fluorescent signals from the polymer may form a signature or fingerprint for a particular polymer. In some such embodiments, such fingerprints may or may not provide sufficient information about the sequence of monomers to be determined.
In some embodiments, a feature of the invention is the labeling of substantially all monomers of a polymer analyte with fluorescent dyes or labels that are members of a pair that quenches each other. The use of the term "substantially all" in relation to labeling polymer analytes is to acknowledge that chemical and enzyme labeling techniques are typically less than 100 percent efficient. In some embodiments, "substantially all" means that at least 80 percent of all monomers have a fluorescent label attached. In other embodiments, "substantially all" means that at least 90 percent of all monomers have a fluorescent label attached. In other embodiments, "substantially all" means that at least 95 percent of all monomers have a fluorescent label attached.
Methods for sequencing polymers such as nucleic acid molecules include the step of providing nanopores or pore proteins (or synthetic pores) inserted into a membrane or membrane-like structure or other substrate. The base or other portion of the pores may be modified with one or more pore markers. The base may point to the transformer side of the pores. Optionally, the cis and / or trans side of the pores may be modified with one or more pore markers. The nucleic acid polymer analyzed or sequenced is a labeled type of nucleic acid polymer in which one of the four nucleotides in the resulting polymer or up to all four nucleotides are labeled analogs of nucleotides. The nucleic acid polymer replaced with (s) may be used as a template for the production. An electric field may be applied to the nanopore to force the labeled nucleic acid polymer through the nanopore, while using an external monochromatic or other light source to illuminate the nanopore, thereby exciting the pore label. As the nucleic acid labeled nucleotides pass through the nanopores, exit the nanopores, or enter the nanopores, or after or before, energy is transferred from the pore labels to the nucleotide labels, resulting in lower energy radiation. Release occurs. Nucleotide-labeled radiation is then detected by a confocal microscope or other optical detection system or optical microscopy system known to those of skill in the art capable of single molecule detection. Examples of such detection systems include, but are not limited to, confocal microscopy, epi-irradiation fluorescence microscopy, and the like. In some embodiments, epi-irradiation fluorescence microscopy is used.
The energy is that the acceptor label of the polymer acceptor-labeled monomer (eg, nucleotide) interacts with the donor label as the labeled monomer exits the nanopore, enters the nanopore, or passes through the nanopore, or before or after. When doing so, the pore or nanopore donor label (eg, quantum dot) may be transmitted to the acceptor label on the polymer (eg, nucleic acid). For example, a donor label may have an interaction or energy transfer between the donor label and the acceptor label until the labeled monomer exits the nanopore and is near or near the donor label outside the channel or opening of the nanopore. It may be positioned or attached to the cis or trans side of the nanopore or the nanopore on the surface so that it does not occur. As a result, the interaction between the labels, the energy transfer from the donor label to the acceptor label, the release of energy from the acceptor label, and / or the measurement or detection of the release of energy from the acceptor label can be measured or detected within the nanopore, eg, the nanopore cis. Alternatively, it may be performed outside the passage, channel, or opening running in the cis or trans chamber on the transformer side. Measurement or detection of the energy emitted from the acceptor label of the monomer may be utilized to identify the monomer.
The nanopore label may be positioned outside the passage, channel, or opening of the nanopore so that the label is visible or exposed to facilitate excitation or illumination of the label. The interaction and energy transfer between the donor and acceptor labels, as well as the release of energy from the acceptor label as a result of energy transfer, can occur outside the nanopore passage, channel, or opening. This is believed to facilitate the ease and accuracy of detection or measurement of energy or light emission from the acceptor label, for example via an optical detection or measurement device.
The donor label may be attached by different methods and / or at different sites on the nanopores. For example, the donor label may be attached or connected directly or indirectly to a portion or unit of nanopore. Alternatively, the donor label may be positioned adjacent to the nanopore.
Each of the acceptor-labeled monomers (eg, nucleotides) of the polymer (eg, nucleic acid) was positioned or placed next to or directly or indirectly on or next to the exit of the nanopore or channel through which the polymer passes. It can interact with the donor label sequentially. Interactions between donor and acceptor labels can occur, for example, after the acceptor-labeled monomer exits the nanopore or before the monomer enters the nanopore, outside the nanopore channel or opening. Interactions can occur, for example, inside or partially inside a nanopore channel or opening while acceptor-labeled monomers pass through the nanopores, enter the nanopores, or exit the nanopores.
When one of the four nucleotides of a nucleic acid is labeled, the time-dependent signal resulting from the release of a single nucleotide label is converted to the sequence corresponding to the position of the labeled nucleotide in the nucleic acid sequence. The process is then repeated for each of the four nucleotides in the individual sample, then the four partial sequences are aligned to assemble the entire nucleic acid sequence.
When analyzing multicolor-labeled nucleic acid (DNA) sequences, the energy transfer from one or more donor labels to each of the four completely different acceptor labels that may be present on the nucleic acid molecule is four completely different wavelengths. Alternatively, the color (each associated with one of the four nucleotides) can result in luminescence, allowing direct sequence readout.
Donor labeling (also referred to herein as "pore labeling") is as close as possible to the aperture (eg, at the exit of the nanopore) without causing obstruction that impairs the transfer of nucleic acid through the nanopore. , May be placed. Pore markings may have a variety of suitable properties and / or properties. For example, the pore label may have energy absorption properties that meet specific requirements. The pore label may have a large radiation energy absorption cross section, for example ranging from about 0 to 1000 nm or about 200 or 500 nm. The pore label may absorb radiation within a specific energy range, such as an acceptor label, which is higher than the energy absorption of the nucleic acid label. The absorbed energy of the pore label may be adjusted relative to the absorbed energy of the nucleic acid label to control the distance at which energy transfer can occur between the two labels. Pore sign is at least 10<sup>6</sup>From 10<sup>9</sup>It may be stable and functional over multiple excitation and energy transfer cycles.
In some embodiments, the device for analyzing the polymer, each with an optical label attached to the sequence of monomers, has the following elements: (a) a solid that separates the first and second chambers. Nanopore arrays in the phase membrane, where the nanopores of the nanopore array provide fluid communication between the first and second chambers, respectively, and each of the different clusters of nanopores is located within a different resolution limit area. And with nanopore arrays arranged in the clusters so that each cluster contains a predetermined number of nanopores with random variables having an average value greater than 1 or greater than zero. b) A polymer migration system for transferring the polymer to the second chamber through the nanopores of the nanopore array in the first chamber, and (c) whenever the optical label exits the nanopores within the resolution limit area. Includes a detection system for collecting optical signals generated by optical labels attached to the polymer. Optically based nanopore sequencing with self-quenching dyes and / or quenchers
In one aspect, the invention includes the use of nanopore arrays with an opaque layer for sequencing and direct illumination of fluorescently labeled polynucleotides. In some embodiments, such applications include fluorescence quenching and fluorescence signaling to sequentially identify the nucleotides of a fluorescently labeled polynucleotide analyte. Such analysis of the polynucleotide analysis may be performed on multiple polynucleotides simultaneously and in parallel, eg, by using an array of nanopores containing an opaque layer. In some embodiments, the nucleotide is labeled with a fluorescent label that can be in at least three states while attached to the polynucleotide: (i) substantially extinguished and taken. The fluorescence of the attached fluorescent label is extinguished by the interaction with the fluorescent label or quenching agent of the adjacent monomer. For example, a fluorescent label attached to a polynucleotide according to the invention is substantially when the labeled polynucleotide is free in a conventional aqueous solution or aqueous buffer for studying and manipulating the polynucleotide. It is extinguished. (ii) In a sterically constrained state, the motion of the free solution or the alignment of the attached fluorescent label is disrupted or limited, with little or no detectable fluorescent signal emanating from the fluorescent label. As such, the labeled polynucleotide is migrating nanopores. (iii) In the transition state, when the fluorescently labeled nucleotide exits the nanopore (during the "transition interval" or "interval"), the fluorescent label attached to the polynucleotide is sterically constrained. A state that transitions from a state to a extinguished state. During the transition interval, the fluorescent label (on a polynucleotide that is otherwise substantially completely labeled, self-quenched or extinguished) can generate a detectable fluorescent signal and is measured. The number of outgoing labels that contribute to the signal can be (at least partially) controlled by controlling the rate of passage of the labeled polynucleotide. If the transit rate (eg, nucleotides leaving the nanopores per millisecond) is faster than the transition rate (from signalable to quenching, ie quenching rate), then the measured fluorescent signal, ie signal sample, is more than one. May include contributions from the label.
Without limiting to any theory supporting the above process, the fluorescent signal generated during the transition interval is due to the presence of one or more freely rotatable dipoles of the fluorescent label emerging from the nanopores. The fluorescent label is therefore capable of generating a fluorescent signal, for example after direct excitation or via FRET-mediated excitation. In some embodiments, the polynucleotide is a single-stranded polynucleotide, such as DNA or RNA, but in particular single-stranded DNA. In some embodiments, the present invention polys by recording the signal generated by a fluorescent label as it exits the nanopore one by one as the polynucleotide translocates through the nanopore. Includes methods for determining the nucleotide sequence of a nucleotide. The transit rate is selected to maximize the likelihood that the measured fluorescence signal will contain fluorescence from virtually only a single label, such selection being a controllable parameter (crossing the nanopores) during the operation. It can be done either by real-time adjustment of voltage, temperature, etc., or by predetermined device settings (eg, reaction buffer viscosity, ion concentration, etc.). Upon exit, each of the attached fluorescent labels transitions from a constrained state in the nanopore to a quenching state in the polynucleotide in free solution during the transition interval. During the transition interval, the label can generate a measurable fluorescent signal. In other words, in some embodiments, the steps of the method may include exciting each fluorescent label as it transitions from the constrained state in the nanopores to the quenching state in the polymer in free solution. As mentioned above, during this transition interval or period, the fluorescent label is capable of emitting a detectable fluorescent signal indicating the nucleotide to which it is attached.
In some embodiments, the "substantially quenched" used above is a fluorescent signal in which the fluorescent label is at least 30 percent less than the signal generated under the same conditions but without the adjacent mutually quenching labels. Means to generate. In some embodiments, the "substantially quenched" used above is a fluorescent signal in which the fluorescent label is at least 50 percent less than the signal generated under the same conditions but without the adjacent mutually quenching labels. Means to generate.
The above concept is shown in Figures 4A-4B. These figures schematically show the labeled polynucleotide (4000) passing through the nanopore (4002). The labeled polynucleotide (4000) comprises two labels "a" and "b" (eg, corresponding to dC labeled "a" and dA, dG and dT labeled "b"). Labeling of nucleotides free from nanopores (4002) is quenched either by interaction with other labels (4011) or by the action of a quencher (not shown). The labeling of nucleotides within the nanopore (4002) is constrained and / or oriented (4014), thereby producing no detectable signal during all or part of its passage through the nanopore. When the nucleotides of the labeled polynucleotide (4000) emerge from the exit (4015) of the nanopore (4002), they are excited by the excitation beam (4010) to generate a detectable signal at intervals before quenching. Will be able to. Passing speed V<sub>1</sub>If is fast, the distance traveled by the nucleotides before extinguishing (4008) exceeds the distance between the nucleotides of the polynucleotide (4000), thereby giving more than one label (shown in Figure 4A) to the detector (4018). Can contribute to fluorescence to the fluorescent signal collected by, i.e., the measured fluorescent signal. Passing speed V<sub>2</sub>If is slow, the distance traveled by the nucleotides before extinguishing (4008) is approximately equal to or less than the distance between the nucleotides of the polynucleotide (4000), thereby no more than one label (shown in Figure 4B). Can contribute to fluorescence to the fluorescent signal (ie, the measured fluorescent signal) collected by the detector (4018). Information on the order of the labels is not available because the distance between adjacent labels is smaller than the diffraction limit of the excitation light (4010), but special algorithms such as Anderson et al., US Provisional Patent Application No. 62/322343; Timp et al. , Biophys. J., Vol. 102, pp. L37-L39 (2012); Carson et al., Nanotechnology, Vol. 26, pp. 074004 (2015) have an approach to infer such information. In the case of optical detection using fluorescent labels with different emission bands, the measured fluorescent signal is divided into two or more channels, for example using a bandpass filter, and fluorescence from multiple labels. Relative contribution of can be evaluated. However, as the number of fluorescent labels that contribute to fluorescence increases, for example, by a factor of 3, 4, or more, the difficulty in determining the correct order of nucleotides increases. The signal intensity corresponding to the maximum emission of two channels, eg, two fluorescent labels, contributes to the signal measured by the two fluorescent labels in Figure 4A (4031 and 4032) and the signal measured by a single fluorescent label. Contribution is shown in Figure 4B (4041 and 4042). The intensity value represented by the solid line, eg 4033, is from the marker "a", and the intensity value represented by the dotted line, eg 4036, is from the marker "b". The presence of solid and dotted lines in both channels in Figure 4A reflects the overlapping emission bands of the fluorescent label, as the amount of intensity measured is from both labels, so this is when collected together. Complicate the analysis. In FIG. 4B, where only a single fluorescent label contributes to the measured signal, the intensity value does not include the contribution of the overlapping emission bands of the other labels, thus facilitating the determination of the label (and thus the nucleotide).
The role of the rate of passage of polynucleotides through nanopores and the need for their control has been recognized in the field of nanopore technology where changes in current are used to identify passing analytes. A wide range of methods have been used to control transit speed, including methods that can be adjusted in real time without significant difficulty (eg, voltage across nanopores, temperature, etc.) and difficulties during operation. Only adjustable methods (thickness of reaction buffer, presence or absence of charged side chains in the bore of protein nanopores, ionic composition and concentration of reaction buffer, attached or hybridized to polynucleotide analysis. Includes speed-reducing groups, molecular motors, etc.). For example, Bates et al., Biophysical J., 84: 2366-2372 (2003); Carson et al., Nanotechnology, 26 (7): 074004 (2015); Yeh et al., Electrophoresis, 33 (23): 58-65 (2012); Meller, J. Phys. Cond. Matter, 15: R581-R607 (2003); Luan et al., Nanoscale, 4 (4): 1068-1077 (2012); Keyser, JR Soc. Interface, 8: 1369-1378 (2011); Incorporated herein for reference. In some embodiments, one or more steps for positively controlling the passing speed during the implementation of the method of the invention, such as voltage, temperature, etc., are included. Other embodiments include one or more steps that determine the passage rate, such as reaction buffer viscosity, ion concentration, etc., which are not actively controlled or varied during the implementation of the methods of the invention. For the latter, the transit rate is selected by providing a reaction buffer having a concentration of glycerol or equivalent reagent in the range of 1-60 percent in some embodiments.
For the former embodiment (real-time transit rate regulation), a measure of whether one or more labels contribute to fluorescence to the measured signal is between multiple channels that collect fluorescence. It may be based on the distribution of the fluorescence intensity of. Typically, the plurality of channels include 2, 3, or 4 channels corresponding to the emission band of the fluorescent label used. In a measured sample of fluorescence emitted from a region adjacent to the exit of the nanopore, if only a single label contributes to the measured signal, then the relative signal intensities between different channels (eg, 4 channels). The target distribution is ideally represented by (1,0,0,0); (0,1,0,0); (0,0,1,0); or (0,0,0,1). Is done. On the other hand, if more than one label contributed to the measured fluorescence signal, the relative distribution would include non-zero values in more than one channel, and in the worst case four different labels would contribute equally. In the above expression, it is expressed as (.25, .25, .25, .25). Relative intensity distribution (1,0,0,0); (0,1,0,0); (0,0,1,0); or (0,0, A scale that can vary monotonically between the maximum value corresponding to 0,1) and the minimum value corresponding to the relative intensity distribution (.25, .25, .25, .25) can be used. For example, the initial passing speed can be reduced based on the value of such a measure that was close to its minimum value. Such reduction may, for example a possible voltage across the nanopore can be carried out by reducing a predetermined amount, the can be recalculated later measure. Such steps can be repeated until the process is optimized.
As mentioned above, the transit rate is exposed to the voltage difference (or electric field strength) across the nanopores and the nanopores (eg, placed in the solid phase membrane constituting one wall of the first chamber) of the polynucleotide. It depends in part on the conditions of the reaction mixture or buffer in the first chamber. The rate of polynucleotide capture by nanopores depends on the concentration of such polynucleotides. In some embodiments, the conditions of the conventional reaction mixture for nanopore sequencing, eg 1M KCl (or equivalent salt such as NaCl, LiCl) and pH buffering system (which ensures that the protein used, for example protein nanopores, nucleases, etc., are not denatured), (changes the voltage across the nanopores). Used with the present invention (to control the passing speed by). In some embodiments, a pH buffering system is used to keep the pH substantially constant at values in the range 6.8 to 8.8. In some embodiments, the voltage difference across the nanopores may range from 70 to 200 mV. In other embodiments, the voltage difference across the nanopores may range from 80 to 150 mV. The appropriate voltage for operation is selected using conventional measurement techniques. The current (or voltage) across the nanopore can be easily measured using a commercially available device. The voltage difference is selected so that the passing speed is within the desired range. In some embodiments, the range of transit speeds comprises less than 1000 nucleotides per second. In another embodiment, the pass rate range is 10 to 800 nucleotides per second; in another embodiment, the pass rate range is 10 to 600 nucleotides per second; in another embodiment, the pass rate. Range is 200-800 nucleotides per second; in another embodiment, the transit rate range is 200-500 nucleotides per second. Similarly, other factors that affect the transit rate, such as temperature, viscosity, ion concentration, charged side chains in the bore of the protein nanopore, etc., can be selected to obtain transit rates in the above range.
In some embodiments, the device for performing the above method for single-stranded nucleic acids is typically a set of electrodes for establishing an electric field across nanopores (which may include an array). Including providing. Single-stranded nucleic acids are exposed to nanopores by placing them in an electrolyte (ie, reaction buffer) in a first chamber configured as the "cis" side of the laminated membrane by placing a cathode in the chamber. Will be done. When an electric field is applied, the negatively charged single-stranded nucleic acid is captured by the nanopores and placed in the chamber to place an anode in the second chamber on the other side of the laminated membrane, which is configured as the "trans" side of the membrane. pass. As mentioned above, the passing speed depends in part on the ionic strength of the electrolyte in the first and second chambers and the voltage applied across the nanopores. In optical-based detection, the pass rate can be selected, for example, by preliminary calibration measurements using predetermined standards of labeled single-stranded nucleic acids that generate signals at different rates expected per nanopore at different voltages. .. Therefore, for DNA sequencing applications, the initial transit rate may be selected based on the signal rate from such calibration measurements, as well as the scale may be based on the relative signal intensity distribution described above. Thus, from such measurements, the voltage at which reliable nucleotide identification is possible or maximum, eg, across an array of nanopores, can be selected. In some embodiments, such calibration can be performed using nucleic acids from the sample of the template being analyzed (instead of or in addition to a given standard sequence). In some embodiments, such calibration may be performed in real time during the sequencing run, and the applied voltage is, for example, real time based on such measurements to maximize the acquisition of nucleotide-specific signals. It may be modified with. Embodiments with Mutual Quenching Markers and Self-Quenching Markers
As mentioned above, in some embodiments, self-quenching and mutual quenching fluorescent labels may be used in addition to the quencher to reduce the emission of fluorescence other than luminescence from the label on the nucleotide exiting the nanopore. can. The use of such fluorescent labels is disclosed in US Patent Application Publication No. 2016/0122812, which is incorporated by reference. In some embodiments, the monomer is labeled with a fluorescent label that can be in at least three states while attached to the target polynucleotide: (i) substantially extinguished. The fluorescence of the attached fluorescent label is quenched by the fluorescent label of the adjacent monomer; for example, the fluorescent label attached to the polynucleotide according to the present invention is the labeled polynucleotide studying the polynucleotide. And when freed in conventional aqueous solutions for manipulation, it is substantially extinguished. (ii) In a sterically constrained state, the motion of the free solution or the alignment of the attached fluorescent label is disrupted or limited, with little or no detectable fluorescent signal emanating from the fluorescent label. As such, the labeled polynucleotide is migrating nanopores. (iii) In the transition state, when the fluorescent label exits the nanopore (during the "transition interval") while the polynucleotide migrates through the nanopore, the fluorescent label attached to the polynucleotide is sterically attached. A state in which the state of transition from the restrained state to the extinguished state.
In some cases, this example is capable of generating a fluorescent signal during the transition interval, which is normally detectable by a fluorescent label (on a polynucleotide that is otherwise substantially completely labeled and self-quenching). It is the application of the discovery that there is. Without limiting to any theory supporting this finding, the fluorescence signal generated during the transition interval is believed to be due to the freely rotatable dipole. Without limiting to any theory supporting this finding, the fluorescence signal generated during the transition interval is believed to be due to the presence of freely rotatable dipoles in the fluorescent label emerging from the nanopores. This allows the fluorescent label to temporarily generate a fluorescent signal, for example after direct excitation or via FRET-mediated excitation. In both the sterically constrained and extinguished states, the dipole has a limited degree of freedom of rotation, thereby reducing or limiting the number of emitted photons. In some embodiments, the polynucleotide is a polynucleotide, usually a single-stranded polynucleotide, such as DNA or RNA, but in particular a single-stranded DNA. In some embodiments, the invention records the signal generated by an attached fluorescent label as it exits the nanopore one by one as the polynucleotide translocates through the nanopore. Thereby comprising a method for determining the nucleotide sequence of a polynucleotide. Upon exit, each of the attached fluorescent labels transitions from a constrained state in the nanopore to a quenching state in the polynucleotide in free solution during the transition interval. In other words, in some embodiments, the steps of the method of the invention excite each fluorescent label as it transitions from a constrained state in nanopores to a quenching state on a polynucleotide in free solution. include. As mentioned above, during this transition interval or period, the fluorescent label is capable of emitting a detectable fluorescent signal indicating the nucleotide to which it is attached.
In some embodiments, the invention forces the fluorescent label attached to the monomer into a constrained state while the polynucleotide is migrating through the nanopores, producing a fluorescent signal in which the fluorescent label is detectable. Includes the application of the discovery that fluorescent labels and nanopores can be selected so that they cannot (or become substantially impossible). In some embodiments, the nanopores are selected to have bores or lumens in the range of 1 to 4 nm in diameter; in other embodiments, the nanopores are bores or or in the range of 2 to 3 nm in diameter. Those with a lumen are selected. In some embodiments, the diameter of such a bore is provided by the protein nanopore. In some embodiments, such nanopores are used to force the fluorescent label into a constrained state in accordance with the present invention, thus substantially generating a fluorescent signal whenever the fluorescent label exits the nanopore. It transitions from a state that cannot be caused to a state that can be detected and identified by a fluorescent signal that can induce emission. Thus, the fluorescent label attached to each of the sequences of the monomers of the polynucleotide is a fluorescent signal in the region immediately adjacent to the exit of the nanopore ("transition zone" or "transition volume" or "detection zone"). Is suddenly generated, so that it can be detected sequentially. In some embodiments, the organic fluorescent dye is used as a fluorescent label with the nanopores of the above diameter. In some embodiments, at least one such organic fluorescent dye is selected from a set consisting of a xanthan dye, a rhodamine dye, and a cyanine dye. Some embodiments for determining the monomer sequence of a polynucleotide are the following steps: (a) Transferring the polymer through nanopores, where the monomer of the polynucleotide is labeled with a fluorescent label and is detectable. A step in which the nanopore constrains the fluorescent label in its bore to a constrained state so that no signal is substantially generated in it; (b) a step in which the fluorescent label of each monomer is excited as it exits the nanopore; (c) In the detection zone, the step of measuring the fluorescence signal generated by the outgoing fluorescent label to identify the monomer to which the fluorescent label is attached; (d) from the fluorescent label excited outside the detection zone. It is carried out in steps of quenching the fluorescent signal of: (d) and determining the monomer sequence of the polynucleotide from the sequence of the fluorescent signal. In a further embodiment, the fluorescent label is an acceptor of the FRET pair and one or more donors of the FRET pair are attached to the nanopores within the FRET distance from the outlet.
In some embodiments, the "substantially quenched" used above is a fluorescent signal in which the fluorescent label is at least 30 percent less than the signal generated under the same conditions but without the adjacent mutually quenching labels. Means to generate. In some embodiments, the "substantially quenched" used above is a fluorescent signal in which the fluorescent label is at least 50 percent less than the signal generated under the same conditions but without the adjacent mutually quenching labels. Means to generate.
In some embodiments, the nucleotide sequence of the target polynucleotide is determined by performing four separate reactions, in which a copy of the target polynucleotide is labeled with a single fluorescent label. It has each of four different types of nucleotides (A, C, G, and T). In variations of such embodiments, the nucleotide sequence of the target polynucleotide is determined by performing four separate reactions, in which a copy of the target polynucleotide is labeled with a single fluorescent label. It has each of its four different types of nucleotides (A, C, G, and T), while the other nucleotides of the same target polynucleotide are labeled with a second fluorescent label. For example, if the first fluorescent label is attached to the target polynucleotide A in the first reaction, the second fluorescent label will be the target polynucleotide C, G, and T (ie, in the first reaction). , "Non-A" nucleotides). Similarly, as a continuation of this example, in the second reaction, the first label is attached to the target polynucleotide C and the second fluorescent label is the target polynucleotide A, G, and T (ie, ie). , "Non-C" nucleotides). The same applies to nucleotides G and T below.
The same labeling scheme can be expressed in terms of conventional technical terms for a subset of nucleotide types; therefore, in the above example, in the first reaction, the first fluorescent label is attached to A and the second fluorescent label is attached. Is attached to B; in the second reaction, the first fluorescent label is attached to C, the second fluorescent label is attached to D; in the third reaction, the first fluorescent label is G. The second fluorescent label is attached to H; in the fourth reaction, the first fluorescent label is attached to T and the second fluorescent label is attached to V.
In some embodiments, polymers such as polynucleotides or peptides are labeled with a single fluorescent label attached to a single type of monomer, eg, all T's (or substantially all) of the polynucleotide. T) is labeled with a fluorescent label, such as a cyanine dye. In such embodiments, the collection or sequence of fluorescent signals from the polynucleotide may form a signature or fingerprint for a particular polynucleotide. In some such embodiments, such fingerprints may or may not provide sufficient information about the sequence of monomers to be determined.
In some embodiments, a feature of the invention is the labeling of substantially all monomers of a polynucleotide analysis with fluorescent dyes or labels that are members of a pair that quenches each other. The use of the term "substantially all" in relation to labeling polynucleotide analyzes is to recognize that chemical and enzyme labeling techniques are typically less than 100 percent efficient. In some embodiments, "substantially all" means that at least 80 percent of all monomers have a fluorescent label attached. In other embodiments, "substantially all" means that at least 90 percent of all monomers have a fluorescent label attached. In other embodiments, "substantially all" means that at least 95 percent of all monomers have a fluorescent label attached. A pair of fluorescent dyes that quench each other have the following properties: (i) each member quenches the fluorescence of all members (eg, by FRET or by stationary or contact mechanism), and (ii) each member. Generates a clear fluorescent signal when excited and when in a non-quenched state. That is, if the pair that quenches each other consists of two dyes, D1 and D2, (i) D1 is self-quenched (eg, by contact quenching with another D1 molecule) and also quenched by D2 (eg, by contact quenching). (Ii) D2 is self-quenched (eg, by contact quenching with another D2 molecule) and is also quenched by D1 (eg, by contact quenching). Guidance for selecting fluorescent dyes or labels for pairs that quench each other can be found in the following references incorporated herein by reference: Johannsson, Methods in Molecular Biology, Vol. 335: pp. 17-29 ( 2006); and Marras et al., Nucleic Acids Research, Vol. 30: e122 (2002) etc. In some embodiments, the members of the set that quench each other include an organic fluorescent dye that is a component or moiety capable of stacking interactions, such as an aromatic ring structure. An exemplary set of fluorescent dyes or labels that quench each other can be selected from rhodamine dyes, fluorescein dyes, and cyanine dyes. In one embodiment, the pair that quenches each other may include a rhodamine dye, TAMRA, and a fluorescein dye, FAM. In another embodiment, the pair of fluorescent dyes that dimming each other are Oregon Green 488, Fluorescein-EX, Fluorescein Isothiocianate, Rhodamine Red-X, Lissamine Rhodamine B, Calcein, Fluorescein, Rhodamine, one or more BODIPY dyes, It may be formed by selecting two or more dyes from the group consisting of Texas Red, Oregon Green 514, and one or more Alexa Fluores. Typical BODIPY dyes include BODIPY FL, BODIPY R6G, BODIPY TMR, BODIPY 581/591, BODIPY TR, BODIPY 630/650, and BODIPY 650/665. Typical Alexa Fluors include Alexa Fluor 350, 405, 430, 488, 500, 514, 532, 546, 555, 568, 594, 610, 633, 635, 647, 660, 680, 700, 750, and 790. Is included. It may be formed by selecting two or more dyes from the group consisting of Red, Oregon Green 514, and one or more Alexa Fluors. Typical BODIPY dyes include BODIPY FL, BODIPY R6G, BODIPY TMR, BODIPY 581/591, BODIPY TR, BODIPY 630/650, and BODIPY 650/665. Typical Alexa Fluors include Alexa Fluor 350, 405, 430, 488, 500, 514, 532, 546, 555, 568, 594, 610, 633, 635, 647, 660, 680, 700, 750, and 790. Is included. It may be formed by selecting two or more dyes from the group consisting of Red, Oregon Green 514, and one or more Alexa Fluors. Typical BODIPY dyes include BODIPY FL, BODIPY R6G, BODIPY TMR, BODIPY 581/591, BODIPY TR, BODIPY 630/650, and BODIPY 650/665. Typical Alexa Fluors include Alexa Fluor 350, 405, 430, 488, 500, 514, 532, 546, 555, 568, 594, 610, 633, 635, 647, 660, 680, 700, 750, and 790. Is included.
As mentioned above, in some embodiments, the monomer sequences of the target polynucleotides have separate reactions, each with a copy of the target polynucleotide having different types of monomers labeled with each other or with a self-quenching fluorescent label. Determined by implementation (one for each type of monomer). In another embodiment, the monomer sequence of the target polynucleotide has each of the different types of monomers labeled with different quenching fluorescent labels, in which copies of the target polynucleotide are selected from the same pair that quenches each other. Determined by performing individual reactions (one for each type of monomer). In embodiments where the mutually quenching pair contains only two dyes, the selected monomer (ie, monomer X) is labeled with the first mutual quenching dye and all other types of monomers (ie, non-monomers). X) is labeled with a second quenching dye from the same set. Thus, the steps of the embodiment generate a series of two different fluorescent signals, a signal indicating monomer X and another signal indicating non-monomer X.
In some embodiments, a single fluorescent label (eg, attached to a single type of monomer in a polynucleotide containing many types of monomers) is a polynucleotide, such as a nucleotide adjacent to the polynucleotide. Those that self-dimming when attached to the adjacent monomer (of the same type) above may be used. Exemplary self-extinguishing fluorescent labels include Oregon Green 488, Fluorescein-EX, FITC, Rhodamine Red-X, Lissamine Rhodamine B, Calcein, Fluorescein, Rhodamine, BODIPYS, and Texas Red, eg Molecular Probes Handbook, 11. Includes, but is not limited to, those disclosed in the edition (2010). Embodiments using a quencher
Various non-fluorescent quenchers, including derivatives of many well-known organic dyes such as asymmetric cyanine dyes, as well as conjugates of such compounds and oligonucleotides and / or analogs thereof, more completely as described below. Is available for use with the present invention. The quencher can be placed in either the cis chamber, the transchamber, or both. Figure 4C shows the following elements: protein nanopores (400) placed in a lipid bilayer (402); an opaque layer (408) in a solid phase membrane (406) to prevent or reduce background fluorescence. Fluorescent sign epi-illumination with; And an embodiment comprising a quencher (410) placed in a transchamber (426). As mentioned above, a polynucleotide (420) containing a fluorescently labeled nucleotide (labeled with an "f" such as (422)) is passed through the nanopore (400) from the cis chamber (424) to the transchamber ( 426) Go through. The oligonucleotide quencher (410) is a condition (eg, concentration, temperature, salt concentration, etc.) that allows hybridization of the oligonucleotide quencher (428) to a portion of the polynucleotide (420) emerging from the nanopore (400). Below, it is placed in the transformer chamber (426). Nanopores (400) are now incorporated herein by Huber et al., So that the signal from the fluorescent label is suppressed during the passage of the nanopores, as described in U.S. Patent Publication No. 2016/0076091. Can be selected. Thus, as labeled nucleotides emerge from the nanopores (400) in the region (428), they are unsuppressed and can generate signals. In most, if not all, forms of direct illumination (eg, non-FRET), such manifested labels continue to move into the transchamber (426) and continue to fluoresce, thereby much for signal collection. To contribute. Quenching agents in the transchamber (426) that bind to the emerging polynucleotide significantly reduce such luminescence, demarcate the detection zone (428) and analyze the signals collected from it to the polynucleotide (420). ) Can be obtained. In some embodiments, the labeled polynucleotide moves through the detection zone and the fluorescent signal from a single fluorescent label is detected from the detection zone (428) during the detection time. In another embodiment, a plurality of fluorescent signals are collected from the plurality of fluorescent labels in the detection zone (428) during a predetermined time. In some embodiments, such detection time is less than 1 msec, or 0. It is less than 1 msec or less than 0.01 msec. In some embodiments, such detection time is at least 0.01 msec, or at least 0.1 msec, or at least 0.5 msec.
The quenchers of the present invention are (i) substantially non-fluorescent under the conditions of nanopore sequencing, (ii) bind to single-stranded nucleic acids, especially single-stranded DNA, and (iii) other molecules. Includes any compound (or set of compounds) that non-radiatively absorbs and emits excitation energy from. In some embodiments, the quencher further binds to the single-stranded DNA in a non-covalent manner. Various quenching compounds, including, but not limited to, non-fluorescent derivatives of common synthetic dyes such as cyanine and xanthene dyes are available for use with the present invention, as more fully described below. be. Guidance on the selection of quenching compounds can be found in references such as US Pat. No. 6,323,337; 6,750,024, which is incorporated herein by reference.
In some embodiments, the quencher is covalently modified with a heavy atom known to quench the fluorescence (such as bromine or iodine), or quenches the fluorescence such as a nitro group or an azo group. May be a single-stranded DNA-binding dye modified covalently by other known groups. Examples of dyes known to bind to single-stranded DNA are Symbr Green (Zipper et al., (2004), Nucleic Acid Research, Vol. 32 (No. 12)). Integration of nitro, bromine, iodine, and / or azo groups into the cyanine Symbr Green structure provides a single-stranded DNA-binding group moiety that quenches fluorescent labels that may be present on the DNA.
In some embodiments, the quencher comprises a binding moiety and one or more quenching moieties. The binding moiety may include any compound that binds to a single-stranded nucleic acid without substantial sequence specificity. Binding moieties can include peptides or oligonucleotides or analogs with modified linkages and / or monomers. Oligonucleotides and their analogs may provide binding to a polynucleotide through the formation of double chains or via non-base pair aptamer binding. In some embodiments, the binding moiety comprises an oligonucleotide or analog thereof having a length in the range of 6-60 nucleotides. Such oligonucleotides or analogs may be conjugated to one quenching moiety or multiple quenching moieties. In some embodiments, the plurality of quenching moieties conjugated to each oligonucleotide or analog is 2 or 3. The quenching portions conjugated to the coupling portions may be the same or different. In some embodiments, whenever the binding moiety is an oligonucleotide or analog, one of the two quenching moieties is conjugated to the 5'end of the oligonucleotide and one to the 3'end. Oligonucleotides or analogs with a few extinguished moieties can be synthesized using conventional ligation and synthetic chemistry, eg, as disclosed in the references cited herein.
Oligonucleotides or analogs can be provided as a single species or as a mixture of multiple oligonucleotides or analogs with different sequences and thus different binding specificities. In some embodiments, the oligonucleotide or analog is a random sequence polymer. That is, they are provided as a mixture of any possible sequences with a given length. For example, such oligonucleotides or analogs are represented by the formula "NNNNNN" for 6 mer or "NNNNNNNN" for 8 mer, where N is A, C, G or T, or similar. It may be a body.
"Analog" with respect to an oligonucleotide means an oligonucleotide containing one or more nucleotide analogs. As described in the definition section, a "nucleotide analog" is a nucleotide that can have a modified linking moiety, sugar moiety, or base moiety. Exemplary oligonucleotide analogs used with the present invention include, but are not limited to, peptide nucleic acid (PNA), locked nucleic acid (LNA) (2'-O-methyl RNA), phosphorothioate oligonucleotides, crosslinks. Includes nucleic acid (BNA) and the like.
In some embodiments, the oligonucleotide binding moiety comprises a universal base. That is, they contain one or more nucleotide analogs that can replace any of the four naturally occurring nucleotides without destabilizing base pair interactions. Nucleotide analogs with universal base properties are described in Loakes, Nucleic Acids Research, Vol. 29 (No. 12), pp. 2437-2447 (2001), which are incorporated herein by reference. In some embodiments, the oligonucleotide binding moieties are 2'-deoxyinosine, 7-deaza-2'-deoxyinosine, 2-aza-2'-deoxyinosine, 3-nitropyrrole nucleotide, 5-nitroindole nucleotide. Etc. are included.
In some embodiments, the quencher may include a combination of two or more compounds that work together to quench the unwanted fluorescent signal of a single-stranded labeled polynucleotide. For example, the quencher can include a labeled polynucleotide and an oligonucleotide that can form a double strand with a double-stranded intercalator that is a separate quencher (eg, polydeoxyinosine). Therefore, whenever polydeoxyinosine binds to a labeled polynucleotide, a quenching intercalator binds to the resulting double chain to quench the fluorescent signal from the polynucleotide.
Any synthetic dye capable of detectively quenching the fluorescent signal of the fluorescent label of the labeled polynucleotide is an acceptable quenching moiety for the purposes of the present invention. Specifically, as used in the present invention, the quenching moiety has an absorption band that exhibits at least some spectral overlap with the emission band of the fluorescent label of the labeled polynucleotide. If sufficient spectral overlap is present, this overlap can occur with the emission of the fluorescent label (donor) that occurs at the emission maximum at a wavelength lower or higher than the maximum absorption wavelength of the quencher portion (acceptor). Energy transfer can also occur through the transition of the donor's luminescence acceptor to a higher electronic state. One of ordinary skill in the art can determine the usefulness of a given quenching moiety by examining the excitation band of the dye with respect to the emission spectrum of the fluorescent label used.
Typically, the fluorescence quenching of the present invention occurs through fluorescence resonance energy transfer (FRET or formation of a charge transfer complex) between the fluorescent label and the quenching moiety of the present invention. The spectral and electronic properties of the donor and acceptor compounds have a strong influence on the degree of energy transfer observed, as well as the separation distance between the fluorescent label and the quencher portion of the labeled polynucleotide. As the separation distance increases, the degree of fluorescence quenching decreases.
The quenching moiety may optionally be fluorescent if the maximum emission wavelength of the dye when bound to the labeled polynucleotide is sufficiently separated from the maximum emission wavelength of the fluorescent label. However, preferably, the quenching moiety is slightly fluorescent or substantially non-fluorescent when covalently conjugated to an oligonucleotide or analog. Substantially non-fluorescent as used herein means that in any of the methods herein, the fluorescence efficiency of the quenching moiety in the analytical solution described is less than or equal to, preferably less than 1 percent. Or equal to it. In other embodiments, the covalently bonded quenching moiety exhibits a quantum yield of less than about 0.1, more preferably less than about 0.01. In some embodiments, the fluorescence of the fluorescent label associated with the quenching of the oligonucleotide of the invention is greater than 50% for the same oligonucleotide associated with the same fluorescent label in the absence of a covalently bound quenching moiety. Is extinguished. In another embodiment, the fluorescent label is quenched by more than 90% of the unlabeled oligonucleotide. In yet another embodiment, nucleic acid staining is quenched by more than 95% of unlabeled oligonucleotides.
In some embodiments, the extinguished moieties are pyrene, anthracene, naphthalene, aclysine, stillben, indole or benzindole, oxazole or benzoxazole, thiazole or benzothiazole, 4-amino-7-nitrobenz-2-oxa-1,3. -Diazol (NBD), cyanine, carbocyanin, carbostyryl, porphyrin, salicylate, anthranilate, azulene, perylene, pyridine, quinoline, coumarin (hydroxycoumarins and aminocoumarins as well as fluorinated and sulfonated ones). (Including derivatives of) (as described in US Pat. No. 5,830,912 of Gee et al. (1998) and US Pat. No. 5,696,157 of Wang et al. Et al. (1988) US Pat. No. 4,774,339; Kang et al. (1993) US Pat. No. 5,187,288; Haugland et al. (1993) US Pat. No. 5,248,782; Kang et al. (1993) US Pat. No. 5,274,113; 1995) 5,433,896; Wu et al. (1999) US Pat. No. 6,005,113, all incorporated by reference), Xanthene, Oxazole or Benz Oxazole, Carbazine (Corey's US Pat. No. 4,810,636 incorporated by reference) (1989). Year))), or phenalenone or benzphenalenone (Babb et al., US Pat. No. 4,812,409 (1989) incorporated by reference).
In other embodiments, the quenching moieties that are substantially non-fluorescent dyes are particularly azo dyes (such as DABCYL or DABSYL dyes and their structural analogs), malachite green or phenol red, 4', 5z-diether. Substituted fluorescein (US Pat. No. 4,318,846 (1982)) or asymmetric cyanine dye quencher (PCT international application WO9937,717 (1999)) is included.
In embodiments where the quenching moiety is a xanthene, the synthetic dye is optionally fluorescein, rodole (Hugland et al., US Pat. No. 5,227,487 (1993) incorporated by reference), or rhodamine. Fluorescein as used herein includes benzo- or dibenzofluoresceins, seminars and fluoresceins, or naphthofluoresceins. Similarly, rodols as used herein include the Seminarhutro dafluols (US Pat. No. 4,945,171 (1990) by Haugland et al., Incorporated by reference). Xanthenes include fluorinated derivatives of xanthene dyes (International Publication No. WO 97/39064 incorporated by reference, Molecular Probes, Inc. (1997)), and sulfonated derivatives of xanthene dyes (International Publication No. incorporated by reference). WO99 / 15517, Molecular Probes, Inc. (1999)) is included. Oxazines used herein include resorhums, aminooxadinones, diaminooxazines, and benzo-substituted analogs thereof.
In a further embodiment, the quenching moiety has one or more aminonitrogen atoms replaced by an aromatic or complex aromatic ring system, eg, described in US Pat. No. 6,399,392, which is incorporated herein by reference. It is a substantially non-fluorescent derivative of 3- and / or 6-aminoxanthene. These quenchers typically have an absorption maximum above 530 nm and have little or no observable fluorescence, eg chemiluminescent, phosphorescent, or broad spectrum emission emitted from the fluorophore. Quench efficiently. In one embodiment, the quenching dye is a substituted rhodamine. In another embodiment, the quenching compound is a substituted rodol.
In yet another embodiment, the quenching moiety is incorporated herein by reference to the following patents, 7,019,129; 7,109,312; 7,582,432; 8,410,025; 8,440,399; 8,633,307; 8,946,404: It may contain one or more non-fluorescent quenchers known as Black Hole Quenchers Compound (BHQ) as described in No. 9,018,369; or No. 9,139,610.
Further quenching moieties are disclosed in US Pat. Nos. 6,699,975; 6,790,945; and 8,114,979, which are incorporated herein by reference.
<p>Passage of Target Polynucleotides in Optically Based Nanopore Sequencing Methods In this example, the invention is used with an exemplary optics-based nanopore sequencing method. An exemplary optical-based nanopore sequencing method labels the nucleotides of a target polynucleotide with a fluorescent label that can be in at least three states: (i) an attached fluorescence in a dimmed state. The fluorescence of the label is extinguished by the fluorescent label of the adjacent nucleotide; for example, the fluorescent label attached to the polynucleotide is extinguished when the labeled polynucleotide is free in the aqueous solution. ing. (ii) In a sterically constrained state, the motion of the free solution or the alignment of the attached fluorescent label is disrupted or limited so that little or no detectable signal is generated from the fluorescent label. In the state where the labeled polynucleotide is migrating nanopores. (iii) In the transition state, when the fluorescent label exits the nanopore (during the "transition interval") while the polynucleotide migrates through the nanopore, the fluorescent label attached to the polynucleotide is sterically attached. A state in which the state of transition from the restrained state to the extinguished state. As the adhered fluorescent labels exit the nanopores one by one as the polynucleotide translocates the nanopores, the signal generated by the fluorescent label is recorded to determine the nucleotide sequence of the polynucleotide. Upon exit, each of the attached fluorescent labels transitions from a constrained state in the nanopore to a quenching state in the polynucleotide in free solution during the transition interval. During this transition interval, the fluorescent label can emit a detectable fluorescent signal indicating the nucleotide to which it is attached.</p><p> In some embodiments, the invention is: (a) extending a primer with a 5'non-complementary tail on a template in a reaction mixture, extending as a single-stranded overhang. With steps to produce double-stranded products containing strands and 5'non-complementary tails; (b) nanopores (or nanopores) that separate the first and second chambers and provide fluid communication between them. An array of), a step in which the nanopore can pass a single-stranded nucleic acid instead of a double-stranded nucleic acid; (c) a step of placing the double-stranded product in the first chamber. And; (d) the step of capturing the 5'non-complementary tail of the separated double-stranded product by the nanopore by applying an electric field across the nanopore; (e) the nanopore with bores and exits. In the step of migrating the polymer analyte through, each polymer analyte contains an array of monomers, substantially each monomer being quenched by the self-quenching of the adjacent monomers by the fluorescent labels of the adjacent monomers. With the step labeled with a fluorescent label so that it is in a state and the fluorescent label is sterically constrained and cannot generate a detectable fluorescent signal inside the nanopore; (f). As each fluorescent label transitions from a sterically constrained state to a quenching state, it is excited at the exit of the nanopore to generate a fluorescent signal indicating the monomer to which the fluorescent label is attached; (g) Can be used with such nanopore sequencing methods using a step of detecting a fluorescent signal to identify a monomer. As used herein, "substantially any," "substantially all," or similar terms refer to the labeling of monomers, especially nucleotides, where the chemical labeling procedure refers to all monomers. It is understood that it does not have to result in complete labeling; to the extent practicable, these terms are understood to continue until the labeling reaction associated with the invention is complete;</p><p> In some embodiments of the above method, the fluorescent label is a member of the FRET pair. FRET pairs are generally one or more FRET donors and one or more FRET acceptors, and each donor can FRET react with each acceptor. In one aspect, the above content means that the donor of the FRET pair has an emission spectrum that substantially overlaps the absorption spectrum of the acceptor. In another aspect, the donor and acceptor transition dipoles must be aligned to allow efficient energy transfer. In some embodiments, the invention partially applies to discover and understand the fluorescence of nanopores, in particular the FRET inhibitory properties, and to detect labeled polymers that migrate through the nanopores. Based on doing. Nanopores may be selected with bores that are sized so that FRET pair labels cannot be oriented to participate in FRET interactions during migration through the nanopores. The invention is not limited thereto. The dipoles of polynucleotide labeling in the bores of nanopores are constrained in their rotational degrees of freedom based on the limited diameter of the nanopores. This reduction in dipole alignment with the alignment of the corresponding FRET pair attached to the nanopore dramatically limits FRET efficiency. The labeled polynucleotide is involved in the FRET interaction after exiting the nanopore in that the FRET acceptor or donor on the polymer (eg, the polynucleotide) regains rotational degrees of freedom to allow the FRET event. Can be done.</p><p> Definition "FRET" or "Forster or Fluorophore Resonance Energy Transfer" means a non-radiopolar-dipole energy transfer mechanism from an excited donor fluorophore to a ground state acceptor fluorophore. The rate of energy transfer in the FRET interaction is the degree of spectral overlap between the donor emission spectrum and the acceptor absorption spectrum, the donor quantum yield, the relative orientation of the donor and acceptor transition bipolars, and the donor molecule. Depending on the distance to the acceptor molecule, Lakowitz, Principles of Fluorescence There is Spectroscopy, 3rd Edition, (Springer, 2006). A FRET interaction of a particular purpose results in a portion of the energy that is transmitted to the acceptor and then emitted by the acceptor as a photon at a frequency lower than the frequency of the light that excites its donor (ie,). "FRET signal"). "FRET distance" means the distance between a FRET donor and a FRET acceptor at which a FRET interaction can be triggered and a detectable FRET signal is generated by the FRET acceptor.</p><p> "Kit" refers to any delivery system for delivering materials or reagents that carry out the methods of the invention. In the context of reaction assays, such delivery systems include fluorescent labels from one location to another, such as reaction reagents (eg, in suitable containers, quenching labels, fluorescent label linking agents, enzymes, etc.). ) And / or include systems that allow storage, transport, or delivery of supporting materials (eg, buffers, documented instruction manuals for performing assays, etc.). For example, the kit contains one or more enclosures (eg, boxes) containing the relevant reaction reagents and / or supporting materials. Such contents are served together or separately to the intended recipient. For example, the first vessel may contain the enzyme used in the assay, while the second or more vessels may contain fluorescent labels that quench each other.</p><p> A "nanopore" allows a substrate to pass through an analyte in a predetermined or identifiable order, or, in the case of a polymeric analyte, its monomer units in a predetermined or identifiable order. Means any opening positioned on the substrate. In the latter case, the predetermined or identifiable order may be the primary sequence of the monomer units in the polymer. Examples of nanopores include protein-like or protein-based nanopores, synthetic or solid-state nanopores, and hybrid nanopores that include solid-state nanopores with protein nanopores embedded therein. The nanopores may have an inner diameter of 1 to 10 nm or 1 to 5 nm or 1 to 3 nm. Examples of protein nanopores include alpha-hemolysin, voltage-dependent mitochondrial porin (VDAC), OmpF, OmpC, MspA, and LamB (maltoporin), eg, Rhee, M. et al., Trends, which are incorporated herein by reference. in Biotechnology, Vol. 25 (4) (2007): 174-181; Bayley et al. (Ibid.); Gundlach et al., US Patent Publication No. 2012/0055792, etc., but limited to these. Not done. Any protein pore that allows the passage of a single nucleic acid molecule may be used. The nanopore protein may be labeled at a specific site outside the pore, or at a specific site outside the one or more monomeric units that make up the pore-forming protein. Pore proteins are selected from a group of proteins including, but not limited to, alpha-hemolysin, MspA, voltage-dependent mitochondrial porin (VDAC), anthrax porin, OmpF, OppC, and LamB (maltoporin). The integration of the pore protein into the hole in the solid state is achieved by attaching the charged polymer to the pore protein. After applying an electric field, the charged complex is drawn into the solid state hole by electrophoresis. Synthetic nanopores or nanopores in the solid state may be created in various forms of solid substrates, such as silicone (eg, Si).<sub>3</sub>N<sub>4</sub>, SiO<sub>2</sub>), Metals, metal oxides (eg Al<sub>2</sub>O<sub>3</sub>), Plastics, glass, semiconductor materials, and combinations thereof, but not limited to these. Synthetic nanopores appear to be more stable than biological protein pores positioned within the lipid bilayer membrane. Synthetic nanopores may be created by using carbon nanotubes embedded in suitable substrates such as, but not limited to, polymerized epoxies. Carbon nanotubes can have uniform and well-defined chemical and structural properties. Carbon nanotubes of various sizes ranging from 1 to 100 nanometers can be obtained. It is known that the surface charge of carbon nanotubes is about zero, which makes the electrophoretic transport of nucleic acids through nanopores simple and predictable (Ito, T. et al., Chem. Communi. 12 (2003). Year): pp. 1482-83). The substrate surface of the synthetic nanopores may be chemically modified to allow covalent attachment of the protein pores or to make the surface properties suitable for optical nanopore sequencing. Such surface modifications can be covalent or non-covalent. Most covalent modifications include organosilane deposits, the most common protocols for which have been described: 1) deposits from aqueous alcohols. This is the easiest way to prepare a silylated surface. A solution of 95% ethanol-5% water with acetic acid at pH 4.5-5. Adjust to 5. Silane is added with stirring to give a final concentration of 2%. After hydrolysis and silanol group formation, the substrate is added for 2-5 minutes. After rinsing, excess material is removed by immersing in ethanol for a short time. The silane layer cures at 110 degrees Celsius for 5-10 minutes. 2) Gas phase deposition. Under dry aprotic conditions, silane can be attached to the substrate by chemical vapor deposition. These methods facilitate monolayer deposition. The closed chamber design heats the substrate to a sufficient temperature to achieve a vapor pressure of 5 mm. Alternatively, a vacuum can be applied until evaporation of the silane is observed. 3) Spin-on deposition. Spin-on adhesion can be carried out under hydrolyzed conditions where maximal source functionalization and multi-layer deposition are preferred, or under dry conditions where monolayer deposition is preferred. In some embodiments, a single nanopore is used in the present invention. In other embodiments, multiple nanopores are used. In some of the latter embodiments, multiple nanopores are used as an array of nanopores, which are usually deposited on a planar substrate such as a solid phase membrane. The nanopores in the nanopore array may be spaced regularly, for example in a linear pattern, or randomly spaced. In a preferred embodiment, the nanopores are regularly spaced as a linear pattern on a planar solid phase substrate. stomach. In a preferred embodiment, the nanopores are regularly spaced as a linear pattern on a planar solid phase substrate. stomach. In a preferred embodiment, the nanopores are regularly spaced as a linear pattern on a planar solid phase substrate.</p><p> "Nanostructures" (used interchangeably with "nanoscale structures" and "nanoscale features") are at least in the range of a few nanometers to a few hundred nanometers, eg, 1 to 1000 nanometers. Means a structure with one dimension. In some applications such a range is 2 to 500 nanometers; in other applications such a range is 3 to 500 nanometers. The shape and geometry of the nanostructures may vary widely and include nanopores, nanowells, nanoparticles, and any other convenient shape that is particularly suitable for carrying out the sequence of reactions. Not limited to. In some embodiments, the nanostructure may be a protein nanopore operably associated with the solid phase membrane. Some nanostructures, such as nanopores and nanowells, may be formed on a larger common substrate such as a solid phase membrane or other solid so that an array of nanopores or nanowells is formed. Nanostructures of particular interest are capable of supporting or containing chemical, physical (eg, FRET), enzymatic, and / or binding reactions, or sequences of such reactions. .. In some embodiments, nanostructures such as nanowells are 1 nanoliter (10).<sup>-9</sup>Surrounds volumes less than (liters), less than 1 picolitre, or less than 1 femtolitre. In other embodiments, each of the individual nanowells provides a volume of less than 1000 zepto liters, 100 zepto liters, 80 zepto liters, or less than 50 zepto liters, or less than 1 zepto liter, or even less than 100 yac liters. In some embodiments, the nanowell comprises a zero-mode waveguide.</p><p> When referring to a peptide, "peptide", "peptide fragment", "polypeptide", "oligopeptide", or "fragment" are used interchangeably herein and are amino acid residues linked by peptide bonds. Refers to the compounds that make up a single non-branched chain of. Amino acids in a peptide or polypeptide may be derivatized with various moieties including, but not limited to, polyethylene glycol, dye, biotin, hapten, or similar moieties. The number of amino acid residues in a protein or polypeptide or peptide may vary widely; however, in some embodiments, the protein or polypeptide or peptide referred to herein is from 2 to 70. It may have amino acid residues; in other embodiments, it may have 2 to 50 amino acid residues. In other embodiments, the proteins or polypeptides or peptides referred to herein are from dozens of amino acid residues, such as 20, up to a thousand or more amino acid residues, such as 1200. It may have an amino acid residue of. In yet other embodiments, the protein, polypeptide, peptide, or fragment thereof may have 10 to 1000 amino acid residues; or they have 20 to 500 amino acid residues. They may have; or they may have 20 to 200 amino acid residues.</p><p> "Polymer" means multiple monomers connected in a straight line. Polymers typically include multiple types of monomers as polynucleotides containing, for example, A, C, G, and T, or as polypeptides containing multiple types of amino acids. Monomers may include, without limitation, nucleosides and their derivatives or analogs, as well as amino acids and their derivatives and analogs. In some embodiments, the polymer is a polynucleotide to which a nucleoside monomer is linked by a phosphodiester bond, or an analog thereof.</p><p> "Polynucleotide" or "oligonucleotide" is used interchangeably and means a linear polymer of nucleotide monomers, respectively. The monomers that make up polynucleotides and oligonucleotides are naturally occurring through regular patterns of monomer-to-monomer interactions, such as Watson-Crick type base pairing, base stacking, or Hoogsteen or reversible Hoogsteen type base pairing. It is possible to specifically bind to a polynucleotide. Such monomers and their nucleoside linkages may occur naturally or may be analogs thereof, eg, naturally occurring or non-naturally occurring analogs. Non-naturally occurring analogs may include PNAs, phosphorothioate nucleoside linkages, and bases containing linking groups that allow attachment of labels such as fluorophores or haptens. Whenever the use of oligonucleotides or polynucleotides requires enzymatic treatment such as elongation with polymerase or ligation with ligase, those skilled in the art will find that the oligonucleotides or polynucleotides are nucleosides at any or several positions in those cases. It will be appreciated that it does not have to contain interlinks, sugar moieties, or nucleotide analogs. Polynucleotides typically range in size from a few monomer units, such as 5-40 units, to thousands of monomer units when they are commonly referred to as "oligonucleotides". Whenever a polynucleotide or oligonucleotide is represented by a sequence of letters (upper or lower case) such as "ATGCCTG", the nucleotides are in the order 5' 3'from left to right and are otherwise indicated from the context. Unless otherwise indicated, "A" indicates deoxyadenosine, "C" indicates deoxycytidine, "G" indicates deoxyguanosine, "T" indicates thymidine, and "I" indicates deoxyinosine. , "U" will be understood to indicate uridine. Professional use unless otherwise stated The word and atomic numbering rules will follow those disclosed in Strachan and Read, Human Molecular Genetics 2 (Wiley-Liss, New York, 1999). Usually, the polynucleotide is four natural nucleosides linked by phosphodiester bonds (eg, deoxyadenosine, deoxycytidine, deoxyguanosine, deoxythymidine for DNA, or their ribose counterparts for RNA). However, they may include, for example, modified bases, sugars, or unnatural nucleotide analogs containing linkages between nucleotides. If the enzyme has specific oligonucleotide or polynucleotide substrate requirements with respect to activity, such as single-stranded DNA, or RNA / DNA duplex, then selection of the appropriate composition for the oligonucleotide or polynucleotide substrate can be used. In particular, it is well within the knowledge of those skilled in the art that the guidelines of articles such as Sambrook et al., Molecular Cloning, 2nd Edition (Cold Spring Harbor Laboratory, New York, 1989) and similar references are well within the knowledge of those skilled in the art. Is obvious. Similarly, oligonucleotides and polynucleotides may refer to single-stranded or double-stranded forms (ie, oligonucleotides or double strands of polynucleotides and their respective complements). It will be apparent to those skilled in the art in the context of the use of the term which form is intended or whether both forms are intended. However, they may include, for example, modified bases, sugars, or unnatural nucleotide analogs containing linkages between nucleotides. If the enzyme has specific oligonucleotide or polynucleotide substrate requirements with respect to activity, such as single-stranded DNA, or RNA / DNA duplex, then selection of the appropriate composition for the oligonucleotide or polynucleotide substrate can be used. In particular, it is well within the knowledge of those skilled in the art that the guidelines of articles such as Sambrook et al., Molecular Cloning, 2nd Edition (Cold Spring Harbor Laboratory, New York, 1989) and similar references are well within the knowledge of those skilled in the art. Is obvious. Similarly, oligonucleotides and polynucleotides may refer to single-stranded or double-stranded forms (ie, oligonucleotides or double strands of polynucleotides and their respective complements). It will be apparent to those skilled in the art in the context of the use of the term which form is intended or whether both forms are intended.</p><p> A "primer" can act as a starting point for nucleic acid synthesis in forming a duplex with a polynucleotide template, extending from its 3'end along the template and thereby extending the duplex. Means a natural or synthetic oligonucleotide that can form. Primer extension is usually performed by nucleic acid polymerases such as DNA polymerase or RNA polymerase. The sequence of nucleotides added in the extension process is determined by the sequence of template polynucleotides. Primers are usually extended by DNA polymerase. Primers typically range in length from 14 to 40 nucleotides, or 18 to 36 nucleotides. Primers are used in various nucleic acid amplification reactions, such as linear amplification reactions using a single primer, or polymerase chain reactions using two or more primers. Guidance on selecting primer lengths and sequences for specific applications is incorporated by reference in the following references: Dieffenbach ed., PCR Primer: A Laboratory It is well known to those of skill in the art, as evidenced by the Manual, 2nd Edition (Cold Spring Harbor Press, New York, 2003).</p><p> The terms "sequencing," "sequencing," or "sequencing nucleotides" or similar terms when referring to a polynucleotide include the determination of partial and complete sequencing information for a polynucleotide. That is, the above term includes sequences of a subset of all sets of four native nucleotides, A, C, G, and T, such as sequences of only A and C of target polynucleotides. That is, the term includes determining the identity, order, and location of one, two, three, or all of the four types of nucleotides within a target polynucleotide. In some embodiments, the term comprises determining the identity, order, and location of two, three, or all four types of nucleotides within a target polynucleotide. In some embodiments, sequencing may be accomplished by identifying the order and location of a single type of nucleotide within the target polynucleotide "catcgc ...", such as cytosine, and thus the sequence. , "C- (Non-c) (Non-c) c- (Non-c) -c ..." will be represented as a binary code such as "100101 ...". In some embodiments, the term may include a sequence of target polynucleotides that act as a fingerprint of the target polynucleotide; that is, the target polynucleotide or target polynucleotide within a set of polynucleotides. A sequence that uniquely identifies a class, eg, all different RNA sequences represented by cells.</p><p> The present disclosure does not limit the scope of the particular form described, but includes alternatives, modifications, and equivalents of the modifications described herein. Moreover, the scope of the present disclosure fully includes other variations that may be apparent to those of skill in the art in light of the present disclosure. The scope of the invention is limited only by the appended claims.</p>
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| US08278055B2 | Cites | United States of America |
| WO2009022152A1 | Cites | World Intellectual Property Organization (WIPO) |
| US20060019247A1 | Cites | United States of America |
| WO2011040996A1 | Cites | World Intellectual Property Organization (WIPO) |
| US20120135410A1 | Cites | United States of America |
| WO2014190322A2 | Cites | World Intellectual Property Organization (WIPO) |
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| WO2017123647A1 | World Intellectual Property Organization (WIPO) | A1 | |
| CN108463560A | China | A | |
| EP3402903A1 | European Patent Office (EPO) | A1 | |
| US2019002971A1 | United States of America | A1 | |
| JP2019504622A | Japan | A | |
| EP3402903A4 | European Patent Office (EPO) | A4 | |
| US11066702B2 | United States of America | B2 | |
| JP6967006B2This record | Japan | B2 | |
| EP3402903B1 | European Patent Office (EPO) | B1 | |
| US2022112551A1 | United States of America | A1 | |
| CN108463560B | China | B | |
| CN108463560B | China | B |
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Numbers
- Publication
- 6967006
- Application
- 2018536442
Titles2
- Japanese
- 低減されたバックグラウンドの光学に基づくナノポア分析
- English
- Nanopore analysis based on reduced background optics
Classification
- CPC, 7
- C12Q1/6869
- G01N21/6408
- G01N21/6428
- G01N2021/6432
- G01N33/48721
- G01N33/48
- G01N2021/6441
- IPC, 5
- C12Q1 6869
- B82Y35 00
- G01N21 64
- G01N33 483
- G01N33 50
