Apparatus for selective agitation of reaction components

DESCRIPTIVE MEMORY

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The present invention relates to an apparatus and method for selective component agitation, for example, an apparatus for suspending the solid phase component in reaction systems containing it or in reagents, particularly in reaction systems for assays. This apparatus is particularly useful in automated testing machines. The invention further relates to a process for performing resuspension of the solid phase.

It is common, for example in hospital laboratories, to carry out a large number of diagnostic reactions on samples from one or more individuals. These reactions are conveniently performed using automated test machines, programmed to perform the necessary tests and present or deliver the results in a printed form.

Typically these machines are provided with supports, for example shelves or carousels that support the containers with the reaction components needed for one or more specific diagnostic tests and / or the samples themselves to be tested.

Many assays, particularly when the assay is an immunoassay, involve a solid component to which a particular reagent may bind or be adsorbed. In many cases, the solid component is a finely divided particulate solid phase which can be suspended in aqueous medium. Obviously, it is desirable, prior to using these solid phase components, to ensure that they are properly suspended, thus avoiding imprecision factors being introduced into the assay.

The art of mixing or resuspending components by vibratory processes is known in the art, for example by means of well-known vibratory mixers which function by placing a sample container in a vibratory element which causes the sample to mix. A commercialized immunoassay system utilizes a reaction vessel suspended from the top by a resilient band. The container base is not

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It is supported and on the contrary is suspended adapted to interact with a mechanical stirrer in order to transmit disturbances to the whole container. In addition, EP 0051341 describes an apparatus comprising a carousel carrying rotating reagent / sample containers in which a number of individual containers are mounted in fixed positions.

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In many systems in the art, one of the problems encountered with a reaction comprising a solid phase component has to do with the cumulative effects of frequent resuspensions and / or the disruption of solid phase reagent life. Over time the solid phase components deteriorate due to particle fragmentation or loss of bound reagent. This is a particularly important problem when, as usual, a support in. carrocei supports different test components, which are not all required for a sample of a given patient and some of which may be used infrequently, so the corresponding reagents are infrequently added. In these situations, systems that vibrate or otherwise disrupt the entire carousel, give rise to resuspensions of the solid phases, regardless of whether they are necessary or not, for a given reaction or test, causing reagent deterioration and ultimately analysis giving rise to inaccurate or poor results. Still another problem in the art is that the suspension caused by vibration is unreliable and may also give rise to inaccurate or poor results, and such a mixing or suspending process may lead to undesirable aeration or foaming.

The present invention provides an apparatus for the selective agitation of one or more components of a multi-component reaction or assay which comprises at least one container for said one or more components which are rotatably mounted on a platform which also supports other components. component containers, said container being at least freely rotatable mounted independently of the other platform-mounted containers, and

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means for selectively rotating said at least one container.

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The present invention in a preferred embodiment provides an apparatus for suspending a particulate solid phase which may be suspended in aqueous medium, which comprises at least one container for said solid phase, supported on a platform which also supports containers. reagents, reaction and / or samples, with at least one container rotatably mounted independently of the other containers placed on the platform, and means for selectively rotating said at least one container. Preferably, the apparatus will be part of an automated immunoassay system, the platform being a carousel carrying containers for use in various immunoassay tests. In especially preferred embodiments, one of said selectively rotatable solid phase containers is provided for each immunoassay test.

The selectively rotatable solid phase container (s) may be mounted on rotating facilitating bearings, for example made of PTFE or polypropylene or other low friction plastics. The containers themselves may be made of these materials, eliminating the need for special bearings, given the low coefficient of friction of the surface of the container (s). These containers may be provided with a base specially configured to pivotably engage a hole or recess provided in the platform.

Preferably, the means for selectively rotating the solid phase container (s) comprises a motor that can drive the container directly or indirectly. An individual motor may be provided for each independently rotatable solid phase vessel, or a single motor may be provided which drives each vessel.

The preferred type of platform is a rotating carousel platform configured to support the containers, and

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which, by simple rotation, can cause a given solid phase container to be aligned with a motorized actuator, placed in a fixed position, thereby allowing selective rotation of a solid phase container independently of the other containers placed on the carousel.

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If desired, other containers can be positioned and mounted so that they can be selectively rotated.

Rotating containers may be rotated by a wheel mounted on a drive shaft connected to a suitable motor. The container is brought into frictional contact with the wheel so that when the engine is started, the wheel rotates the container.

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Alternatively, the container may have an integral gear disposed at its periphery, for example molded at its bottom, which will engage a toothed pinion of the drive shaft.

The apparatus of the present invention may also include means for controlling the rotational movement of the container (s), for example by means of a fixed sensor aligned to detect a light reflected by a reflecting area provided in the container (s). ). 0 The invention further provides for the possibility of controlling and controlling the degree of resuspension of the solid phase by the use of one or more transparent rotating containers and a light absorption or scattering beam measuring system passing therethrough. In general, an information feedback may be provided to a computer operating the apparatus including the rotating containers of the present invention, for example by means of a Hall effect device or an optical reflection device which ensures that the solid phase has been properly stirred. These two sensors may be of the type supplied by RS Components Ltd.

The solid phase container (s) envisaged by the present invention may be supplied separately or as part of complete modules comprising several vessels, for example one or more.

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more liquid reagent containers together with one or more solid phase containers, wherein in each module the containers are preferably all joined by a snap-fit ​​lid on the top adapted to connect the containers to each other and keeping them properly aligned for platform mounting. If desired, at least some of the reagent containers may be supplied integrally as a single molded part. Under these circumstances, a lid may be dispensed with for the purpose of said connection.

In addition, the apparatus of the present invention may be provided with means for closing or sealing the inlet openings of containers, either solid phase containers or other vessels, when not in use. These means may include, but are not limited to, film or plastic material seals, or removable stoppers or lids. A single cover may be employed on multiple containers simultaneously. These means may comprise a movable cover which, when a particular container is not specifically required, may be placed such that the inlet opening is closed. This movable cover may be configured to cover or seal the inlet openings of all containers in at least one module including the solid phase container or containers. 0 movement of the cover may be interconnected with the positioning command of the solid phase container or its rotating means.

Generally, the invention provides for the use of a independently rotatable container, shaking its contents, for example to mix or make suspensions, when carrying out a reaction or assay involving multiple components (e.g., two or more selectively rotating said container in the presence of other adjacent assembled component containers which are not rotatable. In one embodiment, the invention provides such use when applied to the reconstitution of a dry frozen reagent by loading said container with a dry frozen reagent and reconstitution fluid, and

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Performing said selective rotation. Reconstitution of frozen frozen reagents, which are often very unstable, using reconstitution fluids, in accordance with standard practice, are very effective in dissolving such reagents.

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In another preferred aspect, the invention provides for the use of an independently rotatable mounted solid phase container for suspending a particulate solid phase which may be suspended in aqueous medium by carrying out a reaction. or assay, involving multiple components, selectively rotating said container in the presence of adjacent assembled reagent, reaction and / or sample containers.

Centrifugation or spinning of the container need not be confined to a single rotation cycle in one direction. Several rotation cycles may be used, first in one direction and then in the opposite direction. In addition, the rotational speed may be variable to ensure effective resuspension for different types of solid phases.

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Among others, the present invention provides the following advantages compared to existing systems.

(a) It avoids having to use, for example, a diaphragm to transmit vibrations which cause the contents of the container to agitate.

b) Contact between the container and the agitation mechanism is more critical in processes that depend on other processes, for example vibration.

c) The individual containers may be rotated in order to achieve, for example, resuspension of the solid phase, selectively of choice and without shaking the adjacent containers and their contents.

d) Rotation or spinning is simple and mechanically reliable.

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e) A high degree of control of the mixture is possible by centrifugation or rotation through the speed and duration of rotation, degree of acceleration / deceleration, direction of rotation, etc. Centrifugation or rotation raises the solid phase in the fluid or suspension body. By stopping rotation, and then rotating in the opposite direction, highly effective, rapid and controllable resuspension can be achieved. Further improvements are achieved by interposing baffles or other obstructions in the rotating container.

(f) Aeration of the reagent is minimized by centrifugation, thereby minimizing microscopic or surface bubble formation and foaming, and reducing the tendency to obtain inaccurate or mediocre results.

g) Centrifugation or rotation is a gentle mode of agitation, therefore:

(i) the probability of fragmentation of soft or brittle particles is less likely (particles may be composed of weakly agglomerated aggregates of smaller particles);

ii) the likelihood of denaturation of sensitive proteins such as antibodies bound to solid surfaces is less likely; and iii) the probability of creating variable populations of very small (fine) particles that cannot settle within the time available on an automated test instrument is less likely.

h) The engineering of the apparatus is simplified as a centrifuge container can be made of a slippery material such as plastic, for example PTFE or polypropylene, creating self-lubricating bearings.

(i) control of the centrifugation and the degree of suspension of

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resulting solid phase can be done easily and effectively in an automated apparatus.

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In the following the invention will be described with reference to an automated immunoassay equipment. The scope of the invention is not, however, limited to this application.

In the following, the invention will be described with reference to the accompanying drawings, in which:

Fig. 1 is a cross-sectional view of a solid phase container for immunoassay apparatus for use in the invention;

Fig. 2 is a perspective view showing part of an embodiment of an immunoassay apparatus according to the invention using a carousel platform in which reagent blocks and solid phase or reaction vessels are mounted. ;

Fig. 3a is a partially exploded cross-sectional side view showing the arrangement of the various components of the embodiment of Fig. 2;

Fig. 3b is similar to Fig. 3a, but shows a different mechanism for rotating the container;

Fig. 4 is a partially exploded perspective view of an alternative reagent block which may be used in the present invention which includes means for controlling the centrifugation of the container.

Fig. 1 shows a solid phase container 3 capable of receiving a reagent in an automated immunoassay system. The container 3 has an inlet opening 6 through which its contents can be withdrawn, and a part of the base 7, of a given shape allowing it to enter a hole or cavity in the support platform (not shown in this figure) . A preferred material for the construction of this container is polypropylene due to its low coefficient of friction,

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resistance and low weight.

In Fig. 2 shows a part of a platform 1 of the body of an automatic immunoassay machine in which reagent containers 2 are placed and containers 3 shown in Fig. 1. The carousel may be rotated by unrepresented means ( in the direction of the arrow).

In the apparatus of Fig. 2 the means for selectively rotating the solid phase containers 3 is a drive arrangement 12 which drives a wheel 10 through a drive shaft 11. The drive arrangement 12 may be in a fixed or movable position and with or without movement from the motor arrangement 12, the carousel may rotate so as to place the wheel 10 in frictional contact with a particular container 3 such that the motor rotation of the wheel 10 causes the rotation of the solid phase container 3, That's if you wish. Each base part 7 of the containers 3 fits into a corresponding cavity 13 provided in the carousel 1 adjacent to its periphery 9. Due to the slippery nature of the containers 3 they may rotate in the cavities 13.

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Reagent containers · 2 with inlet ports 5 mounted on the carousel 1 are in the form of blocks consisting of two reagent containers 2 together with a corresponding solid phase or reaction vessel 3. The containers 2 and 3 are connected to each other by a snap-on block cover 4 that engages over the reagent container access openings 5 ​​and the solid phase container access opening 6 thereof. Moreover, the nature of this socket does not prevent rotation of the container 3.

In operation of the apparatus, when a given container 3 is brought into contact with the wheel 10, the container 3 is allowed to be selectively rotated or rotated causing a solid phase inside to be suspended without moving. the adjacent containers. In addition, after a given test has been completed (and usually for each

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particular immunoassay test is associated with a block of two reagent containers 2 and a container 3), rotating the carousel 1 to a position corresponding to the desired test below allows wheel 10 to spin a new container 3, when desired.

The immunoassay shown in operation will also require conventional pipette or aspiration means (not shown) to pass reagents from container to container depending on the precise test to be performed. Standard computer control systems that provide the desired sequence of operations (not shown) may be included.

Fig. 3 shows more clearly the interconnection of reagent containers 2, solid phase container 3 and block cap 4. The resulting combination may be referred to as a test or reagent block. Complete blocks may be provided for certain immunoassay tests and individual containers may be replaced by removing block cover 4. These blocks are removably placed on the carousel 1 with the aid of the shaping of the base portions 8 of the reagent containers and the base portion 7 of the solid phase container which fit into the corresponding cavities 17 and 13 provided in the carriage 1.0. solid phase container 3 can rotate freely in its holder. If desired, special bearings 13 (not shown) may be placed in the cavities to facilitate such rotation. These bearings may consist of bushings (not shown) of a plastic having a low coefficient of friction.

An alternate embodiment is shown in Fig. 3b in which the wheel 10 has the configuration of a sprocket which engages a sprocket 18 molded into the lower periphery of the container 3. This allows a more secure engagement between wheel 10 and 3, and thus a more reliable drive transmission provided by motor 12.

Fig. 4 shows the components of another container block.

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according to the present invention consisting of reagent containers 2, a solid phase container 3 which, in use, may be selectively rotated independently of the other containers and a pressure locking reagent block cap 4 which differs shown in Fig. 2 in that it is not cut out. It will be appreciated by those skilled in the art that the configuration of the lid is unimportant, but such a lid allows the various containers to be kept connected together in a given orientation while also allowing them free access. If desired, the block cover may, for example, be reinforced by ribbing. It will also be understood that the pairs of containers 2 of the various figures, if desired for reasons of simplification of construction, can be molded in one piece, possibly eliminating the need for the block lid.

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The embodiment of Fig. 4 also includes means by which the rotation of the solid phase vessels 3 can be controlled which comprise a reflective area 13 located in the solid phase vessel 3 and a fixed sensor 14 for capturing reflected light. The frequency of light captured is proportional to the speed of rotation. This arrangement is particularly useful in automatic testing machines.

Thus, the apparatus according to the present invention permits the selective suspension of a solid phase component of a solid phase containing reaction system without interfering with containers containing other components that are on the same platform or support. This is particularly useful when the reactions in question are performed by automated assay systems, which are usually designed to perform many different test reactions, each of which may have a different solid phase component. However, the invention is not limited to such systems. Selective suspension of only those solid phase components that are required at a given time can be achieved, thereby extending the life of the individual reaction components.

As will be recognized at the same time as the invention provides

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As a flexible solution to the above problems, it can also be easily adapted to particular requirements in terms of the suspension cycle type, number of reaction components for a given reaction, type of vessel support platform, use with different forms of suspension. automatic machines, etc ..