Density phase separation device

IS 2 390 171 T3

DESCRIPTION

Density phase separation device.

BACKGROUND OF THE INVENTION

Field of Invention

The present invention relates to a device for separating heavier and lighter fractions of a sample in fluid. More specifically, this invention relates to a device for collecting and transporting fluid samples whereby the device and the fluid sample are subjected to centrifugation to produce the separation of the heavier fraction from the lighter fraction of the fluid sample. .

Description of the Prior Art

Diagnostic assays may require the separation of a patient's whole blood sample into components, such as serum or plasma (the lightest phase component) and red blood cells (the heaviest phase component). Whole blood samples are typically collected by venipuncture through a cannula or needle attached to a syringe or evacuated blood collection tube. After collection, the separation of blood into serum or plasma and red blood cells is performed by rotating the syringe or tube in a centrifuge. To maintain separation, a barrier must be placed between the oldest and lightest phase components. This allows the separate components to be examined later.

A variety of barriers have been used in collection devices to divide the area between the heaviest and lightest phases of a fluid sample. The most widely used devices include thixotropic gel materials, such as polyester gels. However, current polyester gel serum separator tubes require special manufacturing equipment both to prepare the gel and to fill the tubes. In addition, the shelf life of the product is limited. Over time, the globules can break free from the gel mass and enter one or both of the separated phase components. These globules can clog measuring instruments, such as the instrument probes used during clinical examination of the sample collected in the tube. Additionally, commercially available gel barriers can chemically react with analytes. Consequently, if certain drugs are present in the blood sample when it is taken, an adverse chemical reaction may occur with the gel interface.

Certain chemical separators have also been proposed, in which a mechanical barrier can be inserted between the heavier and lighter phases of the fluid sample. Conventional mechanical barriers are situated between the heaviest and lightest phase components utilizing differential buoyancy and high gravity forces applied during centrifugation. For proper orientation with respect to plasma and serum samples, conventional mechanical separators typically require that the mechanical separator be attached to the underside of the tube closure so that blood filling occurs through or around the device. when coupled with a blood collection set. This attachment is required to prevent premature movement of the retractor during shipping, handling of the drawn blood. Conventional mechanical spacers are attached to the tube closure by a mechanical interlock between the bellows component and the closure. An example of such a device is described in US Patent No. 5,803,022.

Conventional mechanical separators have some significant disadvantages. As shown in Fig. 1, conventional operators include a bellows 34 to provide a seal with the tube or syringe wall 38. Typically, at least a portion of the bellows 34 is housed within, or in contact with, a closure 32. As shown in Fig. 1, as needle 30 passes through closure 32, bellows 34 is depressed. This creates a gap 36 in which blood can pool during insertion or withdrawal of the needle. This can result in a sample pooling under the closure, pre-release of the device in which the mechanical separator is released prematurely during blood collection, trapping a significant amount of fluid phases such as serum or plasma and / or poor sample quality. Furthermore, the above mechanical separators are expensive and complicated to manufacture due to complicated multi-piece manufacturing techniques.

Accordingly, there is a need for a separator device that is compatible with standard sampling equipment and that reduces or eliminates the aforementioned problems of conventional separators. There is also a need for a separator device that can be easily used to separate a blood sample, minimize contamination of the heavier and lighter phases of the sample during centrifugation, and is independent of temperature during storage and transportation. and is stable to radiation sterilization.

SUMMARY OF THE INVENTION

The present invention is directed to an assembly for separating a fluid sample into a higher specific gravity phase and a lower specific gravity phase. Desirably, the mechanical separator of the present invention can be used with a tube, and the mechanical separator is structured to move within the tube under the action of applied centrifugal force in order to separate the parts of a fluid sample. More preferably, the tube is a sample collection tube that includes an open end, a second end, and

ES 2 390 171 T3 a side wall extending between the open end and the second end. The side wall includes an outer surface and an inner surface and the tube further includes a closure arranged to snap into the open end of the tube with a releasable septum. Alternatively, both ends of the tube can be opened, both ends of the tube can be sealed by elastomeric closures. At least one of the tube closures may include a releasable pierceable needle septum.

The mechanical separator may be disposed within the tube at a location between the upper seal and the bottom of the tube. The spacer includes opposite upper and lower ends and includes a float having a pierceable head, a ballast, and a bellows. The components of the separator are sized and configured to achieve an overall density for the separator that falls between the densities of the phases of the fluid sample, such as a blood sample.

In one embodiment, the mechanical separator for separating the fluid sample in the first and second phases within a tube includes a float having a passageway extending between the first and second ends thereof with a pierceable head enclosing the first. end of float. The mechanical separator also includes a ballast that can be moved longitudinally with respect to the float, and a bellows that extends between a part of the float and a part of the ballast, the bellows being adapted for deformation under the longitudinal movement of the float and the ballast. . The bellows of the mechanical separator is isolated from the pierce head. In one embodiment, the float has a first density and the ballast has a second density, where the first density is less than the second density.

The pierceable head of the mechanical spacer is structured to resist deformation under the application of a piercing tip through it. The pierceable head may comprise an edge portion for engagement with the closure and optionally, the edge portion may define at least one notch.

The pierceable head may be received, at least partially, center of the upper recess of the float. The bellows can be circumferentially arranged around at least a part of the float. In one configuration, the pierceable head and the bellows are isolated by a portion of the float. In another configuration, the pierceable head and bellows are insulated by a neck portion of the float. In yet another configuration, the bellows includes an interior wall that defines a restriction surface, and the float includes a step for engaging the restriction surface.

The ballast may define an interlocking recess to accommodate a portion of the bellows for anointing therewith. In this way the bellows and ballast can be secured. Additionally, the ballast may include an outer surface that defines a circumferential annular step disposed within the outer surface to aid in the assembly process.

In one embodiment of the mechanical separator, the float can be made of polypropylene, the pierce head can be made of a thermoplastic elastomer (TPE), such as Kraton®, commercially available from Kraton Polymers, LLC, the bellows can also be made of a thermoplastic elastomer, and the ballast can be made of polyethylene terephthalate (PET).

In another embodiment, a separation assembly to enable separation of a fluid sample into a first and a second phase includes a tube, having an open end, a second end, and a side wall extending therebetween, and a closure adapted for sealing engagement with the open end of the tube. The closure defines a recess and the spacer assembly includes a mechanical spacer releasably engaged with the recess. The mechanical separator includes a float having a passageway extending between the first and second ends thereof with a pierceable head that encloses the first and second ends of the float. The mechanical separator also includes a ballast that can be moved longitudinally with respect to the float, and a bellows that extends between a part of the float and a part of the ballast, the bellows being adapted for deformation under the longitudinal movement of the float and the ballast. . The bellows of the mechanical separator is isolated from the pierce head. In one embodiment the float has a first density and the ballast has a second density, where the first density is less than the second density.

The pierceable head of the float may be structured to resist deformation under the application of a piercing tip through it. In one configuration, the pierceable head and the bellows are isolated by a portion of the float. In another configuration, the pierceable head and the bellows are isolated by a bellows portion of the float. Optionally, the bellows includes an interior wall that defines a restriction surface, and the float comprises a step for engaging the restriction surface. The ballast may define an interlocking recess to accommodate a portion of the bellows for engagement therewith.

In another embodiment, the mechanical separator includes a first subassembly that includes a float having a pierceable head that encloses a first end thereof, and a second subassembly that has a ballast and a bellows. The first subset may have a first density and the second subset may have a second density, the second density being greater than the first density of the first subset. The first sub-assembly and the second sub-assembly can be attached through the bellows so that the ballast can move

ES 2 390 171 T3 longitudinally and with respect to the float under deformation of the bellows. The bellows of the second subassembly is isolated from the pierceable head and the first subassembly.

In yet another embodiment of the present invention, the method of mounting a mechanical spacer includes the steps of providing a first subassembly, the first subassembly including a float with a pierceable neck and head, providing a second subassembly, the second subassembly including a bellows extending from the ballast and including an interior restraining surface, and connecting the first subassembly to the second subassembly. The first subassembly and the second subassembly are joined such that the neck of the float is in mechanical interface with the interior of the restriction surface of the bellows. The float can have a first density and the ballast can have a second density greater than the first density of the float. Optionally, the joining step includes inserting and guiding the float through the interior of the bellows until the neck of the float is at mechanical interface with the interior restraining surface of the bellows. The ballast may also include an outer surface that defines an annular shoulder disposed circumferentially around it to receive a mechanical jointer therein.

In another embodiment of the present invention, a separation assembly to enable separation of a fluid sample in first and second stages includes a closure adapted for sealing engagement with a tube, with the closure defining a recess. The separation assembly also includes a mechanical separator. The mechanical separator includes a float that defines a passageway extending between the first and second ends thereof of a pierceable head that encloses the first end of the float. The pierceable head is releasably engaged with the recess. The mechanical separator also includes a longitudinal ballast that can be moved relative to the float, the ballast having a second density greater than the first density of the float. The mechanical separator further includes a bellows extending between a part of the float and a part of the ballast, the bellows being adapted for deformation under the longitudinal movement of the float and the ballast with the bellows being isolated from the pierceable head.

In one configuration, the interface between the closure and the mechanical spacer occurs only between the pierceable head and the recess. The spacer assembly can also be configured such that the mechanical spacer can be released from the closure without elongation of the deformable bellows. In accordance with another embodiment of the present invention, a mechanical separator for separating a fluid sample in first and second phases within a tube includes a float comprising a passageway extending between a first upward-facing end and a second end. oriented downward. The mechanical separator also includes a ballast that can be moved longitudinally with respect to the float, and a bellows that extends between a part of the float and a part of the ballast, the float being adapted for deformation under the longitudinal movement of the float and the ballast. , and isolated from the first upward facing end of the float.

In accordance with another embodiment of the present invention, a separation assembly to enable separation of a fluid sample into first and second phases includes a tube having an open end, a second end, and a side wall extending between them. The spacer assembly also includes a closure adapted for sealing engagement with the open end of the tube, the closure defining a recess, and a mechanical spacer releasably coupled within the recess. The mechanical separator includes a float having a passageway extending between a first upward facing end and a second downward facing end thereof. The mechanical separator also includes a ballast that can be moved longitudinally with respect to the float and a bellows that extends between a part of the float and a part of the ballast. The bellows is adapted for deformation under longitudinal movement of the float and ballast, and isolated from the first upward facing end of the float. Optionally, the separation assembly is adapted to introduce a fluid sample into the tube and around the mechanical separator without passing through the mechanical separator.

In another embodiment that is not part of the present invention, a mechanical separator for separating a fluid sample into two separate phases within a tube includes a float defining an interior having a movable pin disposed therein. The movable pin is adapted to transition from a first position to a second position along an axis of the float in response to expansion of the fluid sample within the interior of the float.

In one configuration, the float defines a transverse hole and the movable pin defines a transverse hole substantially aligned with the transverse hole of the float in the first position and locked by a portion of the float in the second position. Optionally, the movable pin is restricted within the interior of the float by a pierceable head. The mechanical separator may also include a longitudinally movable ballast with respect to the float, and a bellows extending between a part of the float and a part of the ballast. The bellows can be adapted for deformation under longitudinal movement of the float and ballast and can be isolated from the first end of the float facing upwards.

A further embodiment that does not form part of the present invention, a mechanical separator for separating a fluid sample in a first and second phases within a tube includes a float, a ballast longitudinally movable with respect to the float, and a bellows extending between a part of the float and a part of the ballast. The bellows can

ES 2 390 171 T3 be adapted for low deformation in longitudinal movement of the float and ballast, and may be adapted to at least partially separate from the float to allow ventilation of the gas therein.

The whole of the present invention is advantageous over existing separation products that use separation gel. In particular, the assembly of the present invention does not interfere with analytes, whereas many gels interact with body fluids. Another feature of the present invention is that the set of the present invention will not interfere with the control analytes of the therapeutic drug. The assembly of the present invention is also advantageous over existing spacers in that the separate pierceable head and bellows allow isolation of the sealing function of the bellows from the needle interface of the mechanical retractor. This makes it possible for different materials or different thicknesses to be used to optimize the respective sealing function and the needle interface function. Also, this minimizes device pre-launch by providing a more stable target area at the piercing tip interface to reduce sample build-up under the closure. In addition, pre-launch is further reduced by decompressing the pierce head against the inside of the stop. The reduced clearance between the outside of the float and the inside of the ballast minimizes the loss of trapped fluid phases, such as serum and plasma. Additionally, the assembly of the present invention does not require complicated extrusion techniques during manufacture, and can optimally employ two-cycle molding techniques.

As described herein, the mechanical separator of the present invention does not clog a test probe like traditional gel tubes. Additional details and advantages of the invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a partial sectional side view of a conventional mechanical separator.

Fig. 2 is an exploded perspective view of a mechanical separator assembly including a closure, bellows, ballast, pierceable head, float, and collection tube in accordance with one embodiment of the present invention.

Fig. 3 is a perspective view of the lower surface of the closure of Fig. 2.

Fig. 4 is a cross-sectional view of the closure of Fig. 2, taken along line 4-4 of Fig.

3.

Fig. 5 is a perspective view of the pierceable head of Fig. 2.

Fig. 6 is a top view of the pierceable head of Fig. 2.

Fig. 7 is a side view of the pierceable head of Fig. 2.

Fig. 8 is a cross-sectional view of the pierceable head of Fig. 2, taken along line 8-8 of Fig. 7.

Fig. 9 is a side view of the float of Fig. 2.

Fig. 10 is a cross-sectional view of the float of Fig. 2 taken along line 10-10 of Fig. 9.

Fig. 11 is a close-up cross-sectional view of a part of the float of Fig. 2, taken along section XI of Fig. 10.

Fig. 12 is a top view of the float of Fig. 2.

Fig. 13 is a perspective view of the bellows of Fig. 2.

Fig. 14 is a side view of the bellows of Fig. 2.

Fig. 15 is a cross-sectional view of the bellows of Fig. 2 taken along line 15-15 of Fig. 14.

Fig. 16 is a perspective view of the ballast of Fig. 2.

Fig. 17 is a side view of the ballast of Fig. 2.

Fig. 18 is a cross-sectional view of the ballast of Fig. 2 taken along line 18-18 of Fig. 17.

Fig. 19 is a close-up cross-sectional view of a portion of the bellows of Fig. 2 taken along section IXX of Fig. 18.

Fig. 20 is a perspective view of the mechanical separator including the pierceable head, float, bellows, and ballast in accordance with one embodiment of the present invention.

Fig. 21 is a view of the mechanical separator of Fig. 20.

Fig. 22 is a cross-sectional view of a mechanical separator of Fig. 20, taken along line 22-22 of Fig. 21.

Fig. 23 is a cross-sectional view of the mechanical separator attached to a closure in accordance with one embodiment of the present invention.

Fig. 24 is a partial perspective view in cross-section of a mechanical separator assembly that includes a tube, a mechanical separator located within the tube, a seal, a shield surrounding the seal, and a portion of the tube, a needle that accesses the tube in accordance with one embodiment of the present invention.

Fig. 25 is a front view of an assembly including a tube having a closure and a mechanical spacer positioned therein in accordance with one embodiment of the present invention.

IS 2 390 171 T3

Fig. 26 is a front cross-sectional view of the assembly of Fig. 25 having a needle accessing the interior of the tube and an amount of fluid provided through the needle within the tube in accordance with one embodiment of the present invention.

Fig. 27 is a front cross-sectional view of the assembly of Fig. 25 having the needle removed therefrom during use and the mechanical spacer positioned separate from the closure in accordance with one embodiment of the present invention.

FIG. 27A is a partial front cross-sectional view of an assembly including a tube having a mechanical spacer disposed therein under load in accordance with one embodiment of the present invention.

Fig. 27B is a partial front view in cross section of the assembly of Fig. 27A after configuration.

Fig. 28 is a front cross-sectional view of the assembly of Fig. 25 having the mechanical separator separating the less dense part of the fluid from the denser part of the fluid in accordance with one embodiment of the present invention.

FIG. 29 is a perspective view of an alternate embodiment of a mechanical spacer having a ballast snap engagement in accordance with one embodiment of the present invention.

Fig. 30 is a front cross-sectional view of the mechanical separator of Fig. 29.

Fig. 31 is a front view of the mechanical separator of Fig. 29.

Fig. 32 is a cross-sectional view of the mechanical separator of Fig. 29 taken along line 32-32 of Fig. 31.

Fig. 33 is a cross-sectional view of the mechanical separator of Fig. 29 taken along section XXXII of Fig. 30.

Fig. 34 is an alternative embodiment of the partial cross-sectional view of Fig. 33 having a tapered profile in accordance with one embodiment of the present invention.

Fig. 35 is a front view of the subassembly having a pierceable head portion and a float in accordance with an embodiment of the present invention.

Fig. 36 is a cross-sectional view of the first subassembly of Fig. 35.

Fig. 37 is a perspective view of a second subassembly having a bellows and a ballast in accordance with one embodiment of the present invention.

Fig. 38 is a front cross-sectional view of the second sub-assembly of Fig. 37.

Fig. 39 is a front cross-sectional view of a first assembled subassembly and a second subassembly of a mechanical spacer in accordance with the embodiment of the present invention.

Fig. 40 is a perspective view of the assembled mechanical separator of Fig. 39.

Fig. 41 is a perspective view of a mechanical separator in accordance with one embodiment of the present invention.

Fig. 42 is a front view of the mechanical separator of Fig. 41.

Fig. 43 is a left side view of the mechanical separator of Fig. 41.

Fig. 44 is a rear view of the mechanical separator of Fig. 41.

Fig. 45 is a right side view of the mechanical separator of Fig. 41.

Fig. 46 is a top view of the mechanical separator of Fig. 41.

Fig. 47 is a bottom view of the mechanical separator of Fig. 41.

Fig. 48 is a perspective view of the float of the mechanical separator of Fig. 41.

Fig. 49 is a top perspective view of the pierceable head of the mechanical spacer of Fig. 41. Fig. 50 is a bottom perspective view of the pierceable head of Fig. 49.

Fig. 51 is a cross-sectional front view of the mechanical separator of Fig. 41 located within a closure of the present invention.

Fig. 52 is a front view of a sample collection container having a closure with the mechanical separator of Fig. 41 disposed therein.

Fig. 53 is a front cross-sectional view of the sample collection container, closure and mechanical separator of Fig. 52 taken along line 53-53 of Fig. 52.

Fig. 54 is a cross-sectional view of a closure and a part of a mechanical separator in accordance with one embodiment of the present invention.

Fig. 55 is a perspective view of the top view of the closure of Fig. 54.

Fig. 56 is a bottom view perspective of the closure of Fig. 54.

Fig. 57 is a front cross-sectional view of an alternative closure and a part of a mechanical separator in accordance with one embodiment of the present invention.

Fig. 58 is a cross-sectional side view of the alternative closure of Fig. 57, taken along line 58-58 of Fig. 57 and a portion of a mechanical separator in accordance with one embodiment of the present invention.

Fig. 58A is a front cross-sectional view of the alternative closure of Figs. 57-58 cupped with a collection container thereof having a mechanical separator disposed therein in accordance with one embodiment of the present invention.

Fig. 59 is a partial cross-sectional perspective view of a mechanical spacer having a movable pin disposed within the float in accordance with one embodiment of the present invention.

Fig. 60 is a front cross-sectional view of the float having a movable pin disposed therein of Fig. 59 in an initial position.

IS 2 390 171 T3

Fig. 61 is a cross-sectional view of the float and movable pin of Fig. 60 in an offset position.

Fig. 62 is a partial cross-sectional view of a mechanical separator having a solid float in accordance with one embodiment of the present invention.

Fig. 63. is a front cross-sectional view of the mechanical separator of Fig. 62 disposed within a sample collection container and engaged with a closure.

Fig. 64 is a front cross-sectional view of the mechanical separator of Fig. 63 having a needle disposed through a closure portion to introduce a sample into the sample collection container.

Fig. 65 is a front cross-sectional view of an alternative embodiment of a mechanical separator disposed within a sample collection container having a separating component in accordance with one embodiment of the present invention.

FIG. 66 is a cross-sectional front view of an alternate embodiment of a mechanical separator disposed in a sample collection container having a ribbed shoulder in accordance with one embodiment of the present invention.

Fig. 67 is a front cross-sectional view of an alternate embodiment of a mechanical separator disposed within a sample collection container having a cutout in accordance with one embodiment of the present invention.

Fig. 68 is a partial front cross-sectional view of a mechanical spacer of Fig. 63 having a washer disposed around a portion of the mechanical spacer in accordance with one embodiment of the present invention.

Fig. 69 is a perspective view of a washer of Fig. 68.

Fig. 70 is a perspective view of an alternative embodiment of the washer of Fig. 68.

FIG. 71 is a front cross-sectional view of a sample collection container having a closure engaged therewith and having a mechanical separator disposed therein in accordance with one embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

For purposes of further description, the words "top," "bottom," "right," left, "horizontal," "top," "lateral," "longitudinal," and similar spatial thermals, if used, will refer to the embodiments described as oriented in the drawing figures. However, it is to be understood that many variations and alternative embodiments can be adopted except where expressly specified otherwise. It is to be understood that the specific embodiments and devices described herein are merely exemplary embodiments of the invention.

As shown in the exploded perspective view in FIG. 2, the mechanical separator assembly 40 of the present invention includes a closure 42 with a mechanical separator 44, for use in combination with a tube 46 to separate a fluid sample at first and second stages within a tube 46. Tube 46 may be a sample collection tube, such as a chemistry, molecular diagnostic, or proteomic sample tube , a blood or other body fluid collection tube, coagulation sample tube, hematology sample tube. , and the like. Desirably, tube 46 is an evacuated blood collection tube. In one embodiment, tube 46 may contain additional additives as required for particular assay processes, such as clot inhibiting agents, clotting agents, and the like. Such additives can be in particulate or liquid form and can be sprayed onto the cylindrical side wall 52 of tube 46 or placed on the bottom of tube 46. Tube 46 includes a closed lower end 48, such as a juxtaposed end, an upper end 50, and a cylindrical side wall 52 extending therebetween. The cylindrical side wall 52 includes an inner surface 54 with an inner diameter "a" that extends substantially uniformly from the open upper end 50 to a position substantially adjacent to the closed lower end 48.

Tube 46 can be made of one or more of the following representative materials: polypropylene, polyethylene terephthalate (PET), glass, or combinations thereof. Tube 46 may include a single wall or multiple wall configuration. Additionally, tube 46 can be constructed of any practical size to obtain an appropriate biological sample. For example, tube 46 can be similar in size to large volume tubes, small volume tubes, or micro-container tubes, as is known in the art. In a particular embodiment, tube 46 can be a standard 3 ml evacuated blood collection tube, as is also known in the art.

The open upper end 50 is constructed to at least partially receive the closure 42 therein to form a liquid impermeable seal. The closure includes an upper end 56 and a lower end 50 constructed to be at least partially received in the tube 46. The portions of the closure 42 adjacent the upper end 56 define a maximum outer diameter that exceeds the inner diameter "a" of the tube 46 As shown in Figs. 2-4, the closure portions 42 at the upper end 56 include a central recess 60 defining a pierceable releasable septum. The portions of the closure 42 extending downwardly from the lower end 58 may taper from a smaller diameter that is approximately equal to, or slightly different than, the inside diameter "a" of the tube 46 to a larger diameter that is larger than the inner diameter "a" of tube 46 at upper end

IS 2 390 171 T3

56. In this manner, the lower end 58 of the closure 42 can be pushed into a portion of the tube 46 adjacent to the open upper end 50. The inherent elasticity of the closure 42 can ensure sealing engagement with the inner surface of the cylindrical side wall 52 tube 46.

In one embodiment, the closure 42 may be formed of a molded elastomeric material, having a size and dimensions suitable to provide sealing engagement with the tube 46. The closure 42 may also be formed to define a lower recess 62 that extends into lower end 58. Lower recess 62 may be dimensioned to receive at least a portion of mechanical spacer 44. Additionally, a plurality of spaced arcuate flanges 64 may extend around lower recess 62 to at least partially restrain mechanical spacer 44 therein.

Referring again to Fig. 2, mechanical separator 44 includes a pierceable head 66, a float 68 engaged with a portion of pierceable head 66, a bellows 70 disposed around a portion of float 68, and a ballast 72 arranged around at least a portion of the float 68 and engaged with the bellows 70.

Referring to Figs. 5-8, pierceable head 66 of mechanical spacer 44 may be extruded and / or molded from a self-sealing, elastically deformable material, such as TPE. Pierceable head 66 includes an upper edge portion 76 and a lower portion 78, opposite the upper edge portion 76. The upper edge portion 76 may have a generally curved shape to correspondingly fit the shape of the lower recess 62 of the closure 42, shown in Figs. 3-4. To mitigate pre-launch, pierceable head 66 may be pre-compressed against lower recess 62 of closure 42. In one embodiment, as shown in Fig. 7, top edge portion 76 of pierceable head 66 is angled. curvature A of approximately 20 degrees. In another embodiment, the upper edge portion 76 of the pierceable head 66 includes a slightly tapered or flattened portion 74. The portion 74 may have any suitable dimensions, however, it is preferable that the portion 74 has a diameter between about 3.048mm. (0.120 inches) to approximately 3.81 mm (0.150 inches).

Portion 74 of pierceable head 66 is structured to allow a puncture tip, shown in Fig. 26, such as a needle tip, needle cannula, or probe, to pass through. After removal of the puncture tip from portion 74, pierceable head 66 is structured to reseal itself to provide a liquid impervious seal. The flattened shape of portion 74 allows penetration by the puncture tip without significant deformation. In one embodiment, portion 74 of pierceable head 66 is structured to resist deformation after application of a puncture tip therethrough. The generally curved shape of the upper lip portion 76 and the lower diameter of the portion 74 make the pierceable head 66 of the present invention more stable and less likely to "deform" than the pierceable region of existing mechanical spacers. To further help limit sample build-up and premature release of spacer 44 from lower cavity 62 of closure 42, pierceable head 66 portion 74 may optionally include a thickened region, such as between about 0.254 mm (0.010 inches). at about 0.762 mm (0.030 inches) thicker than the other portions of the upper edge portion 75 of the pierceable head 66.

The pierceable head 66 also includes a bottom portion 78, an opposite upper edge portion 76, structured to engage with at least a portion of the float 68, shown in Fig. 2. The pierceable head 66 may define at least one cutout notch 80 , shown in Figs. 5-6, extending from the upper edge portion 76 to the lower edge portion 78 and from an outer circumference 82 of the upper edge portion 76 to a position 84 circumferentially inward of the outer circumference 82. The cutout notch 80 may be arranged to allow the lip portion 76 of the pierceable head 66 to bend, such as in the application of a puncture tip through the access wall 74, without causing significant arc stress. in pierceable head 66. In one embodiment, a plurality of cutout notches 80 may be disposed at a plurality of locations around the outer circumference 82 of pierceable head 66. A plurality of cutout notches 80 may be capable of causing pierceable head 66 to flex in such a way as to control the releasable load of mechanical spacer 44 from closure 42.

As shown in Figs. 7-8, the upper lip portion 76 of the pierceable head 66 may include an extended portion 82 dimensioned to project from the lower portion 78. In one embodiment, the extended portion 82 of the pierceable head 66 may be sized to have a diameter "B" which is greater than the diameter "c" of the bottom 78. In another embodiment, bottom 78 of pierceable head 66 may be dimensioned for engagement with, such as receiving within, a portion of float 68 as shown in Fig. 2. In still another embodiment, as shown in Figs. 5-6, pierceable head 66 may optionally be vented with a plurality of slits 85 created by a post-mold assembly operation. Pierceable head 66 may include three separate slits 85.

Referring to Figs. 9-12, the float 68 of the mechanical separator 44 is generally a tubular structure 90 having an upper end 86, a lower end 92, and a passageway 94, extending longitudinally therebetween. As shown in Figs. 9-10, the float 68 of the mechanical separator 44 includes an upper end 86 that defines an upper recess 88 to receive the lower portion 78 of the head.

ES 2 390 171 T3 pierceable 66. The upper end 86 of the float 68 has a diameter "d" that may be greater than the diameter "c" of the lower portion 78 of the pierceable head 66, as shown in Fig. 8 , to allow the pierceable head 66 to be received therein. In one embodiment, the diameter "d" of the upper end 86 of the float 68 is less than the diameter "b" of the extended portion 82 of the pierceable head 66, also shown in FIG. 8. In another embodiment, the diameter "e" of the tubular structure 90 of the float 68 is greater than the diameter "b" of the upper edge portion 76 of the pierceable head 66, therefore, the lower portion 78 of the pierceable head 66 can be received within float 68 while the extended portion 82 of pierceable head 66 extends beyond the interior of float 68 when pierceable head 66 and float 68 are engaged. Optionally, the diameter "d" of the float 68 can be equal to the diameter "c" of the pierceable head 66. This may be particularly preferable for two-cycle casting techniques.

The annular engagement of the lower portion 78 of the pierceable head 66 within the recess 88 establishes a mechanical engagement to provide the structural rigidity of the pierceable head 66. Such structural rigidity, in combination with the profile and dimensions of the access portion 74 of pierceable head 66 limits the amount of deformation thereof when a puncture tip is pressed through. In this way, accumulation of the sample and premature release of the separator 44 from the closure 42 can be avoided.

Referring again to Figs. 9-12, the upper end 86 of the float 68 also includes a generally tubular neck 96. The adjacent neck 96, and extending circumferentially about the longitudinal axis L of the float 68 is a step 98 having an outer surface 100. As shown shown in a close-up view in Fig. 11, taken along section XI, in one embodiment, outer surface 100 has a slope at angle B of approximately 29 degrees to facilitate shedding of cells around mechanical separator 44 during centrifugation.

In another embodiment, a plurality of projections 102 may be located around step 98 of float 68. Projections 102 may be a plurality of segmented spacer projections around a circumference of float 68. Projections 102 may create ducts to vent air from the interior of mechanical separator 44 when the mechanical separator is immersed in the fluid during centrifugation. In one embodiment, the vent path is created by a hole or series of holes through a wall in float 68 adjacent to the junction of bellows 70 and float 68.

In one embodiment, it is desirable that the float 68 of the mechanical separator 44 is made from a material that has a lower density than the liquid intended to be separated from two phases. For example, if it is desired to separate human blood into serum and plasma, then it is desirable that float 68 have a density of no greater than about 0.902 gm / cc. In another embodiment, float 46 can be formed from polypropylene. In still another embodiment, pierceable head 66, shown in Figs. 2 and 5-8, and float 68, shown in Figs. 2 and 9-12, can be co-molded, such as two-cycle molded, or co-extruded as a first subassembly.

As shown in Figs. 13-15, the bellows 70 is extruded and / or molded from an elastically deformable material that exhibits good sealing characteristics with the tube material (s). The bellows 70 is symmetrical about its central longitudinal axis C, and includes an upper end 106, a lower end 108, and a hollow interior 104. The bellows 70 also defines the upper end 106 and the lower end 108 for sealing engagement with the cylindrical side wall 52 of the tube 46, as shown in Fig. 2. The bellows 70 may be made of any material sufficiently elastomeric to forming a liquid impervious seal with the cylindrical side wall 52 of the tube 46. In one embodiment, the bellows is TPE and has an approximate dimensional thickness ranging from 0.508mm (0.020 inches) to about 1.27mm (0.050 inches).

The deformable sealing portion 112 may have a generally toroidal shape having an outer diameter "f" which, in an unloaded position, slightly exceeds the inner diameter "a" of tube 46, shown in Fig. 2. However, oppositely directed forces on upper end 106 and lower end 108 will elongate bellows 70, simultaneously reducing the diameter of the deformable seal section to a dimension less than "a". Accordingly, the bellows 70 is adapted to deform under the longitudinal movement of the float 68 in a first direction and the ballast 72 in a second opposite direction.

The bellows 70 may be disposed around, such as disposed circumferentially around, at least a portion of the float 68, shown in Fig. 2. As shown in Figs. 13-15, bellows 70 includes an interior wall 114 within interior 104. Adjacent to upper end 106 of bellows 70, interior wall 114 defines an interior restraining surface 116 for mechanical interface with float step 98, shown in Figs. 912. In one embodiment, the inner restriction surface 116 of the bellows 70, shown in Figs. 13.15, have a slope corresponding to the slope of the step 98 of the float 68, shown in Figs. 9-12.

In this embodiment, the diameter "g" of the opening 115 of the upper end 106 of the bellows 79 defined by the inner wall 114 is smaller than the diameter "d" of the upper end 86 of the float 68, shown in Fig. 9, and smaller than the diameter "e" of the tubular structure 90 of the float 68, also shown in Fig. 9. During centrifugation, the diameter "g" of the bellows 70 increases in size beyond the diameter "d" of the float. and makes possible

The ventilation of air from within the mechanical separator 44. This allows the neck 96 of the float 68, shown in Fig. 9, to pass through the upper end 106 of the bellows 70 but restrains the step 98 of the float 68 against the inner restraining surface 116 of the inner wall 114 of the bellows 70. The tubular structure 90 of the float is not capable of traversing the upper end 106 of the bellows 70.

The outer wall portions of the bellows 70 between the deformable sealing portion 112 and the lower end 108 define a generally cylindrical ballast mounting section 118 having an outer diameter "h" structured to receive the ballast 72 from the mechanical spacer 44 on the same.

As shown in Figs. 16-19, the ballast 72 of the mechanical spacer 44 includes a generally cylindrical section 120 having a bottom surface 112 structured to mate with the ballast mounting section 118 of the bellows 70, shown in Figs. 13-15. In one embodiment, at least a portion of the ballast 72 extends along the ballast mounting section 118 of the bellows 70, as shown in Figs. 13-15. Ballast 72 includes opposite upper and lower ends 124, 126. In one embodiment, upper end 124 includes a recess 128 to receive lower end 108 of bellows 70, shown in Figs. 13-15, in it. The diameter "i" of the recess 128 is greater than the outer diameter "h" of the bellows 70, and the outer diameter "j" of the ballast 72 is less than the inner diameter "a" of the tube 46, as shown in Figs. . 2. Accordingly, the lower end 108 of the bellows 70 can be received within the upper end 124 of the ballast 72 and the mechanical spacer 44, shown in Fig. 2 can be received within the interior of the tube 46, also shown in Fig. 2. In one embodiment, the diameter "i" of the ballast 72 equals the diameter "h" of the bellows 70. Optimally, the ballast 72 can be molded first and the bellows 70 can be subsequently molded into the ballast 72. In one embodiment, the bellows 70 and the ballast 72 have material compatibility such that the bellows 70 and the ballast 72 are bonded together as a result of molding in two cycles.

As shown in Fig. 17, in one embodiment, the ballast 72 may include a mechanical interlocking recess 130 that extends through the generally cylindrical section 120, adjacent to the upper end 124. In another embodiment, the ballast 72 may include mechanical interlocking recess 130 within an interior wall 131, such as within recess 128. A corresponding interlocking joint projection 132 may be disposed on the outer surface of the lower end 108 of the bellows 70, shown in FIG. 15, to mechanically couple the bellows 70 with the ballast 72.

In one embodiment, it is desirable that the ballast 72 of the mechanical separator 44 is made from a material that has a density greater than the liquid intended to be separated into two phases. For example, if it is desired to separate human blood into serum and plasma, then it is desirable that the ballast 72 have a density of at least 1,326 gm / cc. In one embodiment, the ballast 72 can be formed from PET. In still another embodiment, the bellows 70, shown in Figs. 2 and 13-15, and ballast 72, shown in Figs. 2 and 16-19, can be co-molded, such as two-cycle molded, or co-extruded as a second sub-assembly.

In yet another embodiment, the outer surface of the ballast 72 may define an annular recess 134 disposed circumferentially about a longitudinal axis D of the ballast 72 and extending on the outer surface. In this embodiment, the annular recess 134 is structured to allow an automatic assembly to be coupled to the second subassembly, which includes the bellows and ballast for attachment to the first subassembly, which includes the drill head and float.

As shown in Figs. 20-22, when assembled, the mechanical spacer 44 includes a pierceable head 66 engaged with a portion of a float 68, and a bellows 70 circumferentially disposed around the float 68 and engaged with the step 98 of the float 68, and a ballast 72 disposed around float 68 and coupled with a portion of bellows 70. As shown in Figs. 20-22, pierceable head 66 may be partially received within float 68. The bellows 70 can be arranged around the float 68 and the step 98 of the float 68 can be mechanically coupled with the restriction surface 116 of the bellows 70. The ballast 72 can be arranged around the float 68 and at least a part of the bellows 70, and the mechanical interlocking recess 130 and connecting projection 132 can mechanically secure the bellows 70 with the ballast 72. Optimally, the bellows 70 and the ballast 72 can be molded in two cycles and the mechanical interlock can further secure the ballast 72 and the bellows 70.

In one embodiment, the first subassembly including pierceable head 66 and float 68, and the second subassembly including bellows 70 may be separately molded or extruded and subsequently assembled. Maintaining the density of the float within specific tolerances is most easily achieved by using a standard material that does not require composition with, for example, microglass spheres to reduce the density of the material. In one embodiment, the float material 68 is polypropylene with a nominal density of about 0.902 gm / cc. In addition, co-molding, such as two-cycle molding, of the first subassembly and the second subassembly reduces the number of manufacturing steps required to produce the mechanical spacer 44.

As shown in Fig. 23, the assembled mechanical spacer 44 can be pushed into the lower recess 62 of the seal 42. This insert engages the flanges 64 of the seal 42 with the neck 96 of the float 68 or against the head.

ES 2 390 171 T3 pierceable 66. During insertion, at least a portion of pierceable head 66 will deform to conform to the contour of closure 42. In one embodiment, closure 42 is not substantially deformed during insertion of mechanical spacer 44 into the lower recess 62. In one embodiment, the mechanical spacer 44 is engaged with the closure 42 by an interference fit of the pierceable head 66 and the lower recess 62 of the closure 42.

Referring back to Fig. 23, pierceable head 66 and bellows 70 are physically isolated from each other by a portion of float 68, such as neck 96. This isolation allows pierceable head 66 to control both the loading of release from closure 42 as the amount of deformation produced by application of a puncture tip through access portion 74 independent of bellows 70. Similarly, the bellows 70 can control the sealing load with the tube 46, shown in Fig. 2 during applied centrifugal rotation independent of the constraints of the pierceable head 66.

As shown in Figs. 24-25, the subassembly including seal 42 and mechanical spacer 44 is inserted into the upper open end of tube 46 so that mechanical spacer 44 and influencing end 58 of seal 42 are positioned within tube 46. Mechanical spacer 44, which includes bellows 70, will seal the interior of cylindrical side wall 52 and the open upper end of tube 46. The assembly including tube 46, mechanical spacer 44, and closure 42 can then be inserted into a needle holder 136 having a puncture tip 138, such as a needle, extending through it. Optionally, the closure 42 may be at least partially bent by a shield, such as a commercially available Hemogard® Shield from Becton Dickinson and Company, to protect the user from blood dripping on the closure 42 and the effects of generating blood pressure. Potential blood spray when closure 42 is removed from tube 46.

As shown in Fig. 26, a sample of liquid is supplied to tube 46 through puncture tip 138 penetrating the septum of upper end 56 of closure 42 and access portion 74 of pierceable head 66. For purposes of piercing Illustration only, the liquid is blood. The blood will flow through the central passageway 94, the float 68, and the closed lower end 48 of the tube 46. The puncture tip 138 will then be removed from the assembly. After removal of the puncture tip 138, the closure 42 will reseal itself. Pierceable head 66 will reseal itself so that it is substantially impermeable to fluid flow.

As shown in Fig. 27, when the assembly is subjected to an applied rotational force, such as centrifugation, the respective phases of the blood will begin to separate into a denser phase displaced towards the bottom 58 of the tube 46, and a less dense phase displaced towards the upper part 50 of the tube 46. The applied centrifugal force will push the ballast 72 of the mechanical separator 44 towards the closed lower end of the float 68 towards the upper end of the tube 46. This movement of the ballast 72 will generate a longitudinal deformation of the bellows 70. As a result, the bellows 70 will become longer and narrower and will be concentrically spaced inwardly from the inner surface of the cylindrical side wall 52. Consequently, the lighter phase components of the blood will be able to slide the bellows 70 stopped and move up, and similarly, the heavier phase components of the blood will be able to slide past the bellows 70 and move upward. down.

Initially, the neck 96 of the mechanical spacer 44 will be engaged with the flanges 64 of the seal 42. However, after the application of the applied centrifugal force, the mechanical spacer 44 is subjected to a force that acts to release the mechanical spacer from the seal. 42. In one embodiment, the closure 42, particularly the flanges 64, are not dimensionally altered by the application of applied centrifugal force and, as a consequence, are not deformed. It is noted here, that the longitudinal deformation of the bellows 70 during the applied centrifugal force does not affect or deform the pierceable head 66 when the pierceable head 66 and the bellows 70 are isolated from each other by the neck 96 of the float 98.

In one embodiment, referring to Figs. 27A-27B, during centrifugation, the negative buoyancy FLastre of the ballast 72 opposes the positive buoyancy FFloat of the float 68 creating a differential force that the bellows 70 contracts away from the inner surface of the side wall 52 of the tube 46. This elongation of the bellows 70 produces an opening 71 between the float 68 and the sealing surface 73 of the bellows 70 under load. Once the opening 71 is formed between the float 68 and the sealing surface 73 of the bellows 70, as shown in Fig. 27A, the air trapped within the mechanical separator 44 can be vented through the opening 71 to the tube. at a position above the mechanical spacer 44. In this configuration, the bellows 70 deforms away from the float 68 allowing ventilation to occur therebetween. After centrifugation, as shown in Fig. 27B, the bellows 70 elastically returns to the undeformed position and engages by resealing the inner surface of the side wall 52 of the tube 46. Thus, the opening 71 between the float 68 and the sealing surface 73 of the bellows 70 it is sealed when the sealing surface 73 of the bellows 70 contacts the float 68 at the contact surface 75. Referring to Figs. 5-6, during spinning, slits 85 within pierceable head 66 may open due to elongation of the pierceable head portion material, allowing air trapped within the interior of float 68 to be vented therethrough.

IS 2 390 171 T3

As noted above, the mechanical separator 44 has a total density between the densities of the separated phases of the blood. Subsequently, as shown in Fig. 28, the mechanical separator 44 will stabilize at a position within the tube 46 so that the heavier phase components 140 will be located between the mechanical separator 44 and the closed lower end 48 of the tube 46, while the heavier phase components light 142 will be sandwiched between mechanical separator 44 and the upper end of tube 50.

After this stabilized state has been reached, the centrifugation will be stopped and the bellows 70 will elastically return to its unloaded state and sealing engagement with the interior of the cylindrical side wall 52 of the tube 46. The phases can then be accessed separately. liquids formed for analysis.

In an alternative embodiment, as shown in Figs. 29-33, mechanical spacer 44a may include more ballast snap couplings 200 to prevent float 68a from fully passing through bellows 70a under applied load. Ballast snap couplings 200 may be co-molded with ballast 72a to limit movement of float 68a relative to ballast 72a, such as contacting and being constrained by a restriction surface 70x of float 68a under applied load. As shown in detail in FIG. 33, the ballast snap couplings 200 may include a restriction portion 201 for engaging a corresponding recess 202 within the bellows 70a.

In another alternative embodiment, as shown in FIG. 34, the bellows 70b may have a tapered profile 300 adjacent the recess 202 for corresponding engagement with the restriction portion 201 of the ballast snap fittings 200 of the ballast 72b. The tapered profile 300 of the bellows 70b can minimize the pinch formation of the bellows due to the axial movement of the ballast 72b.

In another alternative embodiment, a first assembly 400 including a pierceable head 66c and a float 68c may be molded as shown in Figs. 35-36. The first subassembly 400 may include a relief ring 402 for nesting adaptation with the ballast (shown in Figs. 37-38) to limit relative displacement during assembly and application of accelerated forces. Pierceable head 66c may be provided with a target area dome 403 to reduce deformation and facilitate spillage of debris therefrom. Pierceable head 66c may also be provided with a rigid halo surface 404 to increase launch load and reduce movement of the mechanical spacer during insertion into the closure. As shown in figs. 37-38, the second subassembly 408 that includes the ballast 72c and a bellows 70c may also be co-molded. As shown in Fig. 37, the protrusions 410 on the bellows 70c may engage with corresponding recesses 412 within the ballast 72c to form a locking structure 413 to improve bond strength and securing of the bellows 70c and ballast 72c. . In one embodiment, a plurality of projections 4109 and corresponding recesses 412 are disposed within the bellows 70c and the ballast 72c respectively. As shown in Figs. 37-38, a relief ring 414 may be circumferentially disposed around the ballast 72c to aid in the assembly of the second subassembly 408 with the first subassembly 400, shown in Figs. 35-36.

Assembled mechanical separator 420 is shown in Figs. 39-40 including the attached first subassembly 400 (shown in Figs. 35-36) and the second subassembly 408 (shown in Figs. 37-38). In one embodiment, the assembled mechanical spacer 420 may be sized to fit a 13mm collection tube (not shown).

In accordance with yet another embodiment of the present invention, as shown in Figs. 41-47, a mechanical spacer 500 may include a ballast 572, a bellows 570, a float 568, and a pierceable head 566 as similarly described above. In this configuration, float 568 and pierceable head 566 may be shaped or formed separately and subsequently assembled into a first subassembly, as described above. Referring specifically to Fig. 48, float 568 may include a top 570 having a profile P adapted to receive pierceable head portion 566, shown in Figs. 4950, in a configuration in which the thickness T of the pierceable head portion 566 is substantially uniform across the diameter D of the pierceable head portion 566, shown in Fig. 49. In one configuration, the top 570 of the float 568 may stop a recess 571 and the pierceable head portion 566 may have a corresponding projection 572 to engage the recess 571 of the float 568. In another configuration, the top 570 of the float 568 it may have a protrusion 573, such as a protrusion 573 flanked by corresponding recesses 574. The pierceable head portion 566 may also have a protrusion 575 having a mating surface 576 for abutment with a corresponding surface 577 of the protrusion 573 of the float 568. The protrusion 575 of the pierceable head 566 may also include flanked protrusions 578 to mate with corresponding recesses 574 of float 568. Pierceable head portion 566 may be disposed on top 570 so that the thickness T of pierceable head portion 566 is uniform over opening 579 of float 568. In another embodiment, pierceable head portion 566 may be disposed over the top 570 so that the thickness T of the pierceable head portion 566 is uniform both over the opening 579 of the float 566 and the surrounding rib 581 of the float 566.

Hacienda one sees further reference to Figs. 41-47, ballast 572 and bellows 570 may be shaped or formed separately and subsequently assembled in a second subassembly, as described.

ES 2 390 171 T3 above. In one embodiment, the bellows 570 can include a boss 540, and the ballast 572 can include a corresponding recess 541 to receive the boss 540 therein. Protrusion 540 and recess 541 may be correspondingly coupled to form a locking structure 542, so that ballast 572 and bellows 570 are joined to improve bonding and securing strength. In another embodiment, the bellows 570 may include a plurality of protrusions 540 spaced around a circumference of the bellows 570, and the ballast 572 may include a plurality of corresponding recesses 541 spaced around a circumference of the ballast 572.

The mechanical separator 500, shown in Figs. 41-47 is shown in Figs 51-53 arranged within a sample collection container 530 and a closure 532, as described herein.

As shown in Figs 54-56, an alternative closure 42d can be used with the mechanical separator 420 of the present invention. In one embodiment, the closure 42d includes a receiving well 422 disposed within a portion of the closure adapted to receive a puncture tip (not shown) therein. The receiving well 422 may have any suitable dimensions to aid in centering the closure 42d with the puncture tip. In another embodiment, receiving well 422 may include a tapered profile 423 to orient the puncture tip to center 424 of closure 42d. In yet another embodiment, as shown in Figs 57-58A, an alternative closure 42e may be used with the mechanical separator 420 of the present invention. In this configuration, closure 42e may include an enlarged receiving well 422a adapted to receive a puncture tip (not shown) therein. The seal 42a may also include a chamfered surface 483 adjacent the lower end 421 of the seal 42e to engage a portion of the mechanical spacer 420. In one embodiment, the chamfered surface 483 may include a first angled surface 484 and a second angled surface 485 , with the first angled surface 484 having a greater angle than the second angled surface 485 to enhance the release of the mechanical spacer 420 from the closure 42e.

Another embodiment that is not part of the present invention, shown in Fig. 59, a mechanical spacer 600 may include a pierceable head portion 666, a float, 668, a bellows 670, and a ballast 672 as described herein. In one configuration, float 668 may be provided with a movable pin 620 disposed within an inner portion 622 of float 668. In one embodiment, movable pin 620 can be formed from the same material as float 668, and in another embodiment, movable pin 620 can be formed from a material that has substantially the same density as the density of float 668. In still another embodiment, movable pin 620 may be inserted into an inner portion 622 of float 668 after formation of float 668.

In certain embodiments, a mechanical separator 600 that includes a float 668 having a movable pin 620 may be advantageous. For example, certain assay processes require that the sample be deposited in a sample collection container and that the sample collection container be subjected to centrifugal force to separate the lighter and heavier phases within the sample, as shown. described here. Once the sample has been separated, the sample collection container and the sample placed therein can be frozen, such as at temperatures of about -70 ° C, and subsequently thawed. During the freezing process, the heavier phase of the sample can expand forcing a column of sample to advance upward into the sample collection container and through a portion of the bottom 622 of the float 668 thereby interfering with the barrier arranged between the lightest and heaviest phases. To minimize this volumetric expansion effect, a movable pin 620 may be disposed within the inner portion 622 of the float 668.

The movable pin 620 may be provided with a transverse hole 623 that is substantially aligned with a transverse hole 624 provided in the float 668 in the initial position, shown in Fig. 60, and is substantially blocked by a locking portion 625 of the float. 668 in the offset position, as shown in Fig. 61. In one embodiment, the transverse hole 624 of the movable pin 620 is arranged substantially perpendicular to a longitudinal axis R of the movable pin 668. The movable pin 668 may also be provided with a longitudinal hole 626 that is substantially aligned with the inner portion 622 of float 668 to allow the sample to be directed therethrough after introduction of a sample into the mechanical separator, as discussed above.

Referring to Fig. 60, in the initial position a sample is introduced into the mechanical separator provided within the sample collection container (not shown) through the pierceable head portion 666, through the longitudinal hole 626 of the movable pin 620 and through inside 622 of float 668. After sampling and during the application of centrifugal force to the mechanical separator, the air trapped within the inner part 622 of the float can be vented through the transverse hole 623 of the movable pin and the transverse hole 624 of the float 668 and released from mechanical separator 600. Specifically, air can be vented from between float 668 and bellows 670 as described herein.

Referring to Fig. 61, once the sample is separated into the lighter and denser phases within the sample collection container (not shown) the sample can be frozen. During the freezing process, the densest part can expand upwards. To prevent the denser part advanced upward from interfering with the lighter phase, and to prevent the denser part of the sample from escaping from float 668, the

ES 2 390 171 T3 movable pin 620 advances upward with the expansion of the densest phase of the sample. As the movable pin 620 is advanced upward, the transverse hole 623 of the movable peg 620 aligns with the locking portion 625 of the float 668, which prevents the sample from slipping out of the movable peg 620 and the inner portion 622 from float 668 through hole 623. The movable pin 620 is adapted to advance with the expanded column of denser material present within the inner portion 622 of the float during freezing. It is anticipated here that the movable pin 620 may be restricted at an upper limit of the pierceable head portion 666, shown schematically in Figs. 59-61. In this configuration, the elasticity of pierceable head portion 666 acts as a stretchable balloon to constrict movable pin 620 within mechanical spacer 600.

Advancement of movable pin 620 can be fully passive and in response to externally applied sample freezing conditions. In certain cases, movable pin 620 may also be arranged to return to its initial position after subsequent thawing of the sample.

Another embodiment that is not part of the present invention, as shown in Figs. 62-64, a mechanical separator 700 may include a bellows 770, a ballast 772, as described herein, and a solid float 768 that does not require a pierceable head portion. In this configuration, it is anticipated that the mechanical separator 700 may be constrained within the sample collection container 720 in an initial position. In one configuration, the mechanical separator 700 may be constrained within with the sample collection container 720 due to frictional interference with a portion of the side wall 722 of the sample collection container 720. In another embodiment, the collection container Sample 720 may include a first part 724 having a first diameter E and a second part 726 having a second diameter F, the first diameter E being greater than the second diameter F. In this configuration, the mechanical separator 700 may be constrained at the interface of the first part 724 and the second part 726. During the introduction of a sample into the sample collection container 720, a needle 730 pierces a closure part 740 and introduces a sample into the interior 745 of the sample collection container 720. It is anticipated herein that the needle 730 does not pierce the float 768 but instead introduces the sample on an upper surface of the float 768. The sample is then directed around the mechanical separator 700 and passes into the lower portions of the sample collection container 720. After the sample is introduced into the interior 745 of the sample collection container 720, the needle is withdrawn and the closure it closes again. After the application of centrifugal force, the mechanical separator 700 disengages from a restricted position with the side wall 722 of the sample collection container 720 after deformation of the bellows 770 as described herein. In one configuration, at least one of the mechanical separator 700 and the sample collection container 720 may include a recess to allow the sample to pass between the mechanical separator 700 and the side wall 722 of the sample collection container 720 during the introduction of the sample.

According to yet another embodiment that is not part of the present invention, as shown in Fig. 65, a separation component 800 may be disposed between a portion of the bellows 770 and the side wall 722 of the sample collection container 720. to assist in at least one of the restriction of the bellows 770 with the side wall 722, and the passage of the sample around the bellows 770 after the entry of the sample into the sample collection container. In this configuration, the spacer component 800 may be a sleeve having an angled portion 801 adapted to allow the sample to pass around it. In accordance with another embodiment, as shown in FIG. 66, the sample collection container 720 may include a ribbed projection 802, such as a plurality of radially spacer rib bosses 802, spacer inwardly from a portion of the side wall. 722. Ribbed protrusion 802 may allow a sample to wander around while at least a portion of bellows 770 is constrained by side wall 722 of sample collection container 720. In accordance with yet another embodiment, as shown in Fig. 67, sample collection container 720 may include cutout 804, such as a plurality of radially spaced cutouts 804, within a portion of side wall 722. The cutouts 804 may allow the sample to pass through while a portion of the side wall 722 of the sample collection container 720 restrains at least a portion of the bellows 770.

In accordance with yet another embodiment that is not part of the present invention, as shown in Figs, 6870, the mechanical separator 700 may be constrained against the side wall 722 of the sample collection container 720 by a washer 806. The washer 806 can constrain a portion of the mechanical spacer 700 such as a portion of the float 768 through an opening 810 in the washer 806. Washer 806 can restrain mechanical spacer 700 with side wall 722 through an interference fit. Optionally, washer 806 may be attached to side wall 722 of sample collection container 720. The washer 806 is configured to restrain the mechanical separator 700 with a portion of the sample collection container 720 and to allow the sample to pass around the mechanical separator 700 when it is inserted into the sample collection container 720. The washer 806 can retain the mechanical separator 700 in such a way as to substantially prevent the mechanical separator 700 from obstructing the flow of the sample to the sample collection container 720. Specifically, the washer 806 can hold the mechanical separator 700 in place within the sample collection container 720 so that the sample can pass between the bellows of the mechanical separator 700 and the side wall 722 of the sample collection box 720. Washer 806 can be used with a sample collection container 700 that has a first part that has a larger diameter and a second part that has a smaller diameter as shown here. In this configuration, washer 806

ES 2 390 171 T3 can prevent the bellows of the mechanical separator 700 from clogging the joint of the first part and the second part of the sample collection container 720, such as when the sample collection container 720 "bends its neck down" . In this configuration, washer 806 prevents mechanical separator 700 from plugging the sample path in sample collection container 720.

In one embodiment, washer 806 includes a plurality of doors 820 adapted to allow passage of the sample therethrough, as shown in Fig. 69. In another embodiment, washer 806 includes a cutout 822 adapted to allow the passage of the sample between the washer 806 and a portion of the side wall 722 of the sample collection container 720, as shown in FIG. 70.

In accordance with yet another embodiment that is not part of the invention, as shown in Fig. 71, in certain embodiments a portion of the side wall 912 of the sample collection container 900 may include a boss 914. Optionally, the opposing parts of the side wall 912 may include opposing projections 914 adapted to allow a sample entering the sample collection container 900 to pass around a part of the bellows 916 of a mechanical separator 918 disposed therein. In this configuration, a portion of the side wall 912 having a substantially straight profile may contact a portion of the bellows 916 to secure the mechanical spacer 918 within the sample collection container 900 through an interference fit. Another portion of the side wall 912 of the sample collection container 900, such as the opposing portions of the side wall 912, may include opposing projections that have an outwardly curved profile to allow the sample to pass between the side wall 912 and the bellows 916. In this configuration, the portion of the bellows 916 aligned with the opposing projections 914 does not touch the side wall 912 of the sample collection container 900, establishing a space 920 for sample flow therein. Although the present invention has been described in terms of a medical spacer disposed within the tube adjacent the open end, it is also contemplated herein that the mechanical spacer may be located at the bottom of the tube, such as attached to the bottom of the tube. This configuration can be particularly useful for plasma applications where the blood sample does not clot, because the mechanical separator is capable of moving through the sample during centrifugation.