GB2494860A - An array of PCR wells and an array of caps for such a well array - Google Patents

Abstract

A flexible array 30 of wells 32 suitable for Polymerase Chain Reactions wherein each well 32 in the array 30 is connected to adjacent wells in a first direction by a respective pair of curved arms 34 and is connected to adjacent wells in a second direction by a respective tear point 42. The curved arms 34 enable the distance between adjacent wells 32 to remain unchanged when the array 30 is thermally cycled while the wells 32 are friction fitted in apertures (20, Fig. 1) of a support frame. The tear points 42 are formed of two triangles 48 with one edge of each triangle 48 connected with a well 32 and opposing points of the triangles 48 connected together. The tear points 42 allow the array 30 to be separated into strips of wells 32. Also disclosed is a cap mat (Figs. 24-44) for sealing the wells of the above array. The cap mat comprises an array of caps wherein each cap in the array is connected to adjacent caps in a first direction by a respective pair of curved connecting arms and is connected to adjacent caps in a second direction by a respective connecting tear point.

Description

Improved Plate

Field of the Invention

The present invention relates to multi-well plate systems used as containers for chemical or biological reactions, such as the Polymerase Chain Reaction (FOR) or for storage of chemical or biochemical samples, and to methods of manufacturing such plates. It is applicable to multi-well plates used as containers for chemical or biological reactions, such as real-time quantitative FOR (qPCR), and in particular to multi-well plate systems comprising separate frames, flexible plates and flexible sealing caps and mats and to their manufacture.

Background of the Invention

Multi-well plates, or two-dimensionally bound arrays of wells or reaction chambers, are commonly employed in research and clinical procedures for the screening and evaluation of multiple samples. Multà-well plates are especially useful in conjunction with automated thermal cyclers for performing FOR and qPCR, and for other techniques such as DNA cycle sequencing and the like. They are also highly useful for biological culturing of micro-organisms and assay procedures, and for performing chemical synthesis on a micro scale.

Multi-well plates may have wells or tubes that have single openings at their top ends, similar to conventional microtubes or they may incorporate second openings at the bottom ends which are filled with frits or filter media to provide a filtration capability. As implied above, multi-well plates are most often used for relatively small-scale laboratory procedures and are therefore also commonly known as "microplates". Example multi-well plates are disclosed in ER 0638364, GB 2288233, US 3907505 and US 4968625.

Multi-well plates for FOR and qPOR use are typically comprised of a plurality of plastic tubes arranged in rectangular planar arrays of typically 3 x 8 (a 24-well plate), 6 x 8 (a 48-well plate) or B x 12 (a 96-well plate) tubes with an industry standard 9 mm (0.35 in.) centre-to centre tube spacing (or fractions thereof). As technology has advanced plates with a larger number of wells have been developed such as 16 x 24 (a 384-well plate).

In PCR and qPCR multi-well plates, the bottoms of the tubes are generally of a rounded conical shape. They may alternatively be flat-bottomed (as typical with either round or square-shaped well designs used with optical readers).

A horizontally disposed tray or plate portion (usually described as the deck) generally extends integrally between each tube, interconnecting each tube with its neighbour in a cross-web fashion. Typically, the plate is of a solid construction with holes only provided where wells are located or to assist in robotic handling. The perimeter of the plate portion is commonly formed with a skirt extending downwardly beneath the plate portion, although non-skirted plates also exist. When a skirt is provided it may either be a semi-skirted or fully skirted version. The skirt is integrally formed with the plate portion during moulding of the plate and generally forms a continuous wall of constant height around the plate. Fully-skirted plates offer stability when placed on a surface, whereas both semi and fully skirted plates offer improved rigidity for plate handling and reduced warping during thermal cycling.

Research techniques that use multi-well plates include, but are not limited to, quantitative binding assays, such as radioimmuniassay (RIA) or enzyme-linked imrriunosorbant assay (ELISA), combinatorial chemistry, cell-based assays, thermal cycle DNA sequencing, POR and qPCR both of which amplify a specific DNA sequence using a series of thermal cycles.

Each of these techniques makes specific demands on the physical and material properties and surface characteristics of the sample wells. For instance, RIA and ELISA require surfaces with high protein binding; combinatorial chemistry requires great chemical and thermal resistance; cell-based assays require surfaces compatible with sterilization and cell attachment, as well as good transparency for certain applications; and thermal cycling requires low protein and DNA binding, good thermal conductivity, and moderate thermal resistance.

Compatibility of these plates with automated equipment has become increasingly important, since many laboratories automate the filling, and emptying of the wells, which often contain five microlitres or less of a sample, as well as their handling. Accordingly, it is desirable to use a multi-well plate that is conducive to use with robotic equipment and which can withstand robotic gripping and manipulation.

In the case of multi-well plates intended for PCR and qPCR use there is a further important requirement, which is that the well walls should be as thin as possible. Such thin-wall microplates are designed to accommodate the stringent requirements of thermal cycling and are designed to improve thermal transfer to the samples contained within the sample wells. The sample wells are typically conical shaped to allow the wells to nest into corresponding conical shaped heating/cooling blocks of the thermal cyclers. The nesting feature of sample wells helps to increase surface area of the thin-wall microplates while in contact with the heating/cooling blocks and thus helps to facilitate heating and cooling of samples.

It will therefore be appreciated that thin-wall microplates require a specific combination of physical and material properties for optimal robotic manipulation, liquid handling, and thermal cycling. These properties consist of rigidity, strength and straightness required for robotic plate manipulation; flatness of sample well arrays required for accurate and reliable liquid sample handling; physical and dimensional stability and integrity during and following exposure to temperatures in excess of 100°C (if the microplate is heat sealed for example the microplate will be exposed to temperatures of around 170C and the plate itself can often reach temperatures of 120C); and thin-walled sample wells required for optimal thermal transfer to samples. These various properties tend to be contradictory. For instance polymers offering improved rigidity and/or stability typically do not possess the material properties required to be biologically compatible and/or to form thin-walled sample tubes.

Typically PCR and qPCR plates are manufactured by one-piece polymer injection moulding because of the cost-effectiveness of this process. Various structural features are incorporated into the microplates in order to improve the strength, rigidity and flatness of the end product. For example, ribs may be incorporated into the underside of the multi-well plates to reinforce flatness and rigidity. However, such structural features are limited in their size and shape by the requirement that such plates must fit into various thermal cyclers produced by a number of manufacturers. A further option to enhance rigidity and flatness of multi-well plates includes using polymers that naturally impart rigidity and flatness to the plates. However, the selected polymer must also meet the physical and material property requirements of thin-wall microplates in order for the plates to function correctly during thermal cycling.

In practice, most PCR and qPCR plates in use today are manufactured from a polyalkene, typically polypropylene, in a one-shot injection moulding process. Polypropylene is used because the flow properties of molten polypropylene allow consistent moulding of a sample well with a wall that is sufficiently thin to promote optimal heat transfer when the sample well array is mounted on a thermal cycler block. In addition, polypropylene does not soften or melt when exposed to the high temperatures of thermal cycling. However, thin-wall microplates constructed in this way from polypropylene or polyethylene possess inherent internal stresses which are found in moulded parts with complex features and which exhibit thick and thin cross sectional portions throughout the body of the plate. These internal stresses result from differences in cooling rates of the thick and thin portions of the plate body after the moulding process is complete. In addition, further distortions such as warping and shrinkage due to the release of these internal stresses can result when thin-wall microplates are exposed to the conditions of the thermal cycling process. The resultant dimensional variations in both flatness and the footprint size can lead to unreliable sample loading and sample recovery when using automated equipment. The warping and shrinkage that occurs during the thermal cycling process is not only problematic where robotic handling occurs, but also particularly where qPCR is employed. qPCR uses a combination of fluorescent markers located in the sample in the wells and detection apparatus located outside the wells which detect the fluorescence of the fluorescent markers. In one example fluorescent markers are adapted to bind to DNA and fluoresce only once they are bound. There are, however, a number of other reactions which can be utilized to release the fluorescent marker from, for example, a quencher into the sample solution. Thus the level of fluorescence detected can be used to quantitatively access in real time the amount of DNA that has been amplified in the reaction. This requires the wells, and lids covering the wells, to be located in exactly the same position throughout the full thermal cycling process. Thus, any warping or shrinkage which may occur will have an effect on the position of the wells and lids and in turn affect the fluorescence readings.

One option to improve the rigidity is to incorporate structural features into the multi-well plates which might include incorporating ribs on the undersides of multi-well plates to reinforce flatness and rigidity. However, such structural features cannot be incorporated into thin-wall microplates used in thermal cycling procedures. Such structural features would not allow samples wells to nest in the wells of thermal cycler blocks and, therefore, would prevent effective coupling with block wells resulting in less effective thermal transfer to samples contained within sample wells.

Another option to enhance rigidity and flatness of multi-well plates includes using suitable, economical polymers that impart rigidity and flatness to the plates. Simultaneously the selected polymer must also meet the physical and material property requirements of thin-wall microplate sample wells in order for such sample wells to correctly function during thermal cycling. Many prior art multi-well plates are constructed of polystyrene or polycarbonate. Polystyrene and polycarbonate resins exhibit mould-flow properties that are unsuitable for forming the thin walls of sample wells that are required of thin-wall microplates. Moulded polystyrene softens or melts when exposed to temperatures routinely used for thermal cycling procedures. Therefore, such polymer resins are not suitable for construction of thin-wall microplates for thermal cycling procedures.

UK 2288233 (Akzo Nobel NV.) describes a type of microtitre plate where an array of microtitre wells sit within a grid of square holes, each hole being adapted to accommodate a well. The grid of holes form an integrated part of a skirted frame portion. Such an arrangement would be impractical for FOR and qFCR plates since the assembled unit would not and could not function within a thermal cycler.

Various other attempts have been made in the prior art to overcome these problems. One such example is described in EP 1198293 (M J Research Inc.) which describes a thin-wall microplate formed from a skirt and frame portion which accommodates a separate well and deck portion, which may be joined to form the unitary plate. In this way, the skirt and frame portion can be formed of a rigid plastics material and the separate well and deck portions can be formed of the standard polypropylene plastics material. Thus, when the unitary product goes through the thermal cycling process the skirt and frame portion remains as it was before the thermal cycling process. The problem is that the separate well and deck portion still undergoes warping and shrinkage and can twist and move within the skirt and frame portion. Therefore, although this product overcomes any changes which might affect robotic handling of the microplate, it does not overcome all of the problems associated with FOR, qPOR and thermal cycling in general.

Other manufacturers have attacked the problem by providing a first component formed from a rigid plastics material which comprises a skirt, frame and first deck portion. The first deck portion simply being a plurality of holes where the wells will be located. The second component is formed of the standard polypropylene plastics material and comprises the wells and a second deck portion. The concept being that the rigid plastics first deck portion will keep the second component in position during the thermal cycling process. The problem is that the forces involved in the warping and shrinkage processes are so strong that this arrangement is still not sufficient to prevent movement of the wells. An example of a plate of this type which has undergone thermocycling is shown in Figure 60 to show the problem still occurs.

Another such example is described in ER 1161994 (Eppendorf AG) which describes a thin-wall microplate formed by 2-shot injection moulding. The skirt, frame and deck portions are integrally moulded from a rigid plastics material. The thin walled wells are then formed by moulding a second plastics material directly to holes in the deck portion, which is typically the standard polypropylene plastics material. The problem is that shrinkage and warping of the individual wells will still occur which leaves open the possibility that one or more wells may become detached from the deck during use.

Furthermore with the variety of operations and reaction conditions available to the scientist there is an increasing requirement to operate on a variable number of samples. In addition, it is often necessary to carry out subsequent operation(s) on just a portion of samples which have undergone a first processing. In order to achieve this the samples must be subdivided into subsets for further investigation/reaction. This can currently be achieved by using a number of small plate arrays to total 96 and by selecting just some of the plate arrays for subsequent processing. For example, one could choose two 3 x 8 plates and one 6 x B plate to give a fill 96-well cycler.

Alternatively, a conventional 96-well plate can be used and this can be physically cut up into smaller arrays at a suitable point or points in the process. However, both these methods have inherent disadvantages.

Firstly, pre-selecting plate blocks requires considerable pre-planning and also presupposes the results of the first set of reactions. Once chosen, there is no subsequent flexibility as to the number in each block. In addition, this method greatly increases the number of manual handling operations since each block must be picked up separately. Furthermore, these smaller blocks are generally not amenable to robotic handling, whilst conventional 96 and 384 multi-well plates are routinely handled robotically.

Cutting up conventional plates has the advantage that the size of the subsets can be determined by the operator at any time, providing increased flexibility. However, once the plates have been cut manually they can only be placed in a thermal cycler in their original orientation. Inevitable irregularities in the cuts means the subsets will only fit together to reform the original plate. Manual cuts are never entirely straight and the misalignment of adjacent blocks prevents them sitting properly in the cycler in anything other than their original configuration. This is usually overcome by leaving a gap of one row of wells between adjacent blocks. This in itself is unsatisfactory because it means that extra runs of the cycler may need to be carried out to make up for the empty rows.

Attempts have been made to overcome these problems such as in ER 1053790 (Advanced Biotechnologies Ltd) which provides a microplate comprising one or more section lines in predetermined regions. The section lines being adapted to facilitate dividing up the microplate into sub-units of a predetermined size. The section lines are devoid of material in the main and simply having joining nodules. The nodules are then "snapped" or cut to divide up the microplate. The problem is that the nodules only snap when cold and tend not to snap with the nodules on the same porhon leaving the same problems discussed above regarding the lack of symmetry.

Another attempt to try to overcome both the issues regarding rigidity and plate division is found in ER 1754538 which has all the same individual problems raised above.

Summary of the Invention

According to a first embodiment of the present invention there is provided a plate component for RCR reactions, comprising a plurality of discrete wells arranged in an array, wherein each well in the array is connected to another well in the array in a first direction by a connecting arm and in a second direction by a connecting tear point. Preferably the connecting arm is longer than the distance between the wells and is curved. The curvature of the connecting arm is preferably adapted to change under thermal cycling conditions such that the distance between the wells remains unchanged. This enables the plate component to undergo a thermal cycle reaction such as POll or qPCR without the plate component undergoing any warping which effects the distance between the wells which occurs in prior art plates. This is particularly beneficial in thermal cycle reactions where the

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sample in the well needs to be continuously monitored throughout the reaction and any change in the position of the well could have an impact on the variable being monitored.

Preferably each well in the array is connected to another well in the array in a first direction by two connecting arms. This not only enables the plate component to undergo a thermal cycle reaction such as FOR or qPCR without the plate component undergoing any warping which effects the distance between the wells which occurs in prior art plates, but also lends stability to the plate component and improves sample handling as multiples of 8 samples can be picked up together rather than individual tubes.

Preferably the wells are connected together in the first direction by a connecting arm to form a strip wherein preferably each strip of wells is separable from the plate component by means of the connecting tear point. Preferably the connecting tear point is adapted to separate into two equally sized portions during separation an equally sized portion remaining connected to each strip. This not only facilitates dividing up the microplate into sub-units of a predetermined size, but also results in the sub-units being symmetrical such that each sub-unit can be placed next to any other sub-unit in the thermal cycler without any misalignment between the sub-units. The tear point is also able to undergo contraction/expansion during the thermal cycle process which further assists in maintaining the distance between the wells of the plate component.

According to a second embodiment of the present invention there is provided a cap mat for sealing wells in FOR reactions, comprising a plurality of discrete caps arranged in an array, wherein each cap in the array is connected to another cap in the array in a first direction by a connecting arm and in a second direction by a connecting tear point. Preferably the connecting arm is longer than the distance between the caps and is curved. The curvature of the connecting arm is preferably adapted to change under thermal cycling conditions such that the distance between the caps remains unchanged. This enables the cap mat to undergo a thermal cycle reaction such as PCR or qPCR without the cap mat undergoing any warping which effects the distance between the caps. This is particularly beneficial in thermal cycle reactions where the sample in the well needs to be continuously monitored throughout the reaction and any change in the position of the cap could have an impact on the variable being monitored.

Preferably each cap in the array is connected to another cap in the array in a first direction by two connecting arms. This not only enables the cap mat to undergo a thermal cycle reaction such as PCR or qPCR without the cap mat undergoing any warping which effects the distance between the caps, but also lends stability to the cap mat.

Preferably the caps are connected together in the first direction by a connecting arm to form a strip wherein preferably each strip of caps is separable from the cap mat by means of the connecting tear point. Preferably the connecting tear point is adapted to separate into two equally sized portions during separation an equally sized portion remaining connected to each strip. This not only facilitates dividing up the cap mat into sub-units of a predetermined size, but also results in the sub-units being symmetrical such that each sub-unit can be placed next to any other sub-unit in the thermal cycler without any misalignment between the sub-units. The tear point is also able to undergo contraction/expansion during the thermal cycle process which further assists in maintaining the distance between the caps of the cap mat. Furthermore the cap mats are easier for the user to handle, and easier and faster to apply than 12 individual strips. In addition the correct number of cap strips required from the cap mat can readily be selected in comparison to adhesive seals which need to be measured and cut to the correct size.

According to a third embodiment of the present invention there is provided a multi-well plate assembly for use in POR reaction comprising a plate component and a frame component wherein the frame component is adapted to support the plate component.

The plate component comprises a plurality of discrete wells arranged in an array, wherein each well in the array is connected to another well in the array in a first direction by a connecting arm and in a second direction by a connecting tear point. Preferably the connecting arm is longer than the distance between the wells and is curved. The curvature of the connecting arm is preferably adapted to change under thermal cycling conditions such that the distance between the wells remains unchanged when the plate is retained in the frame component described below. This enables the plate component to undergo a thermal cycle reaction such as PCR or qPCR without the plate component undergoing any warping which effects the distance between the wells which occurs in prior art plates. This is particularly beneficial in thermal cycle reactions where the sample in the well needs to be continuously monitored throughout the reaction and any change in the position of the well could have an impact on the variable being monitored.

Preferably each well in the array is connected to another well in the array in a first direction by two connecting arms. This not only enables the plate component to undergo a thermal cycle reaction such as PCR or qPCR without the plate component undergoing any warping which effects the distance between the wells which occurs in prior art plates, but also lends stability to the plate component.

Preferably the wells are connected together in the first direction by a connecting arm to form a strip wherein preferably each strip of wells is separable from the plate component by means of the connecting tear point. Preferably the connecting tear point is adapted to separate into two equally sized portions during separation an equally sized portion remaining connected to each strip. This not only facilitates dividing up the microplate into sub-units of a predetermined size, but also results in the sub-units being symmetrical such that each sub-unit can be placed next to any other sub-unit in the thermal cycler without any misalignment between the sub-units.

Preferably the frame component comprises a deck portion, a skirt portion and a frame portion. The deck portion preferably comprises a plurality of apertures each aperture being adapted to receive and retain a well of the plate component or separated strip or block of strips thereof. This assists in retaining the wells of the plate portion in a fixed position in the frame portion such that when the plate component to undergoes a thermal cycle reaction such as PCR or qPCR the plate component doesn't undergo any warping which effects the distance between the wells, which occurs in prior art plates. This is particularly beneficial in thermal cycle reactions where the sample in the well needs to be continuously monitored throughout the reaction and any change in the position of the well could have an impact on the variable being monitored.

Brief Description of the DrawinQs

Figure 1 is a perspective view of the frame component; Figure 2 is a top plan view of the frame component; Figure 3 is a bottom plan view of the frame component; Figure 4 is a front view of the frame component; Figure 5 is a side view of the frame component; Figure 6 is a perspective view of the plate component; Figure 7 is a top plan view of the plate component; Figure 8 is a bottom plan view of the plate component; Figure 9 is a front view of the plate component; Figure 10 is a side view of the plate component; Figure 11 is a perspective view of the plate component located above the frame component; Figure 12 is a perspective view of the plate component partially located in the frame component; Figure 13 is atop plan view of the plate component with a magnified portion; Figure 14 is a perspective view of the plate component with one strip in a partially separated position; Figure 15 is a perspective view of the plate component with one strip in a separated position; Figure 16 is a perspective view of the plate component with a block of three strips in a separated position; Figure 17 is a perspective view of the plate component which has had one strip removed with a magnified portion; Figure 18 is a perspective view of the plate component which shows the end strip n section with a magnified portion; Figure 19 is a perspective view of the plate component fully located in the frame component; Figure 20 is a top plan view of the plate component fully located in the frame component; Figure 21 is a front view of the plate component fully located in the frame component; Figure 22 is a side view of the plate component fully located in the frame component; Figure 23 is a bottom plan view of the plate component fully located in the frame component; Figure 24 is a top perspective view of the cap mat; Figure 25 is a top plan view of the cap mat; Figure 26 is a bottom perspective view of the cap mat; Figure 27 is a bottom plan view of the cap mat; Figure 28 is a front view of the cap mat; Figure 29 is a side view of the cap mat; Figure 30 is a top perspective view of the cap mat with a magnified portion; Figure 31 is a top plan view of the cap mat with a magnified portion; Figure 32 is a top perspective view of the cap mat with one strip in a separated position; Figure 33 is a top perspective view of the cap mat with a block of three strips in a separated position; Figure 34 is a top perspective view of the cap mat which shows the end strip in section with a magnified portion; Figure 35 is a perspective view of the cap mat in a partially installed position on the plate component; Figure 36 is a perspective view of the cap mat in a fully installed position on the plate component; Figure 37 is a perspective view of the cap mat in a fully installed position on the plate component; Figure 38 is a top plan view of the cap mat in a fully installed position on the plate component; Figure 39 is a side view of the cap mat in a fully installed position on the plate component with a portion shown in section and a magnified portion thereof; Figure 40 is a side view of the cap mat in a fully installed position on the plate component; Figure 41 is a bottom plan view of the cap mat in a fully installed position on the plate component; Figure 42 is a perspective view of the cap mat in a fully installed position on the plate component fully located in the frame component; Figure 43 is a perspective view of the cap mat in a fully installed position on the plate component fully located in the frame component; Figure 44 is a top plan view of the cap mat in a fully installed position on the plate component fully located in the frame component; Figure 45 is a front view of the cap mat iii a fully installed position on the plate component fully located in the frame component with a portion shown in section and a magnified portion thereof; Figure 46 is a side view of the cap mat in a fully installed position on the plate component fully located in the frame component; Figure 47 is a bottom plan view of the cap mat in a fully installed position on the plate component fully located in the frame component; Figure 48 is a perspective view of the frame component with a separate strip of the plate component and cap mat and a separated block of three strips of the plate component and cap mat located therein; Figure 49 is a perspective view of a separated block of two strips of the plate component and cap mat; Figure 50 is a top plan view of a separated block of two strips of the plate component and cap mat; Figure 51 is a side view of a separated block of two strips of the plate component and cap mat; Figure 52 is a front view of a separated block of two strips of the plate component and cap mat; Figure 53 is a bottom plan view of a separated block of two strips of the plate component and cap mat; Figure 54 is a perspective view of the cap mat fully installed on a first alternate standard plate; Figure 55 is a perspective view of the cap mat fully installed on a second alternate standard plate; Figure 56 is a perspective view of the plate component fully located in the frame portion with an alternate standard adhesive film seal in a partially installed position; Figure 57 is a perspective view of the plate component fully located in the frame portion with an alternate standard adhesive film seal in a fully installed position; Figure 58 is a front view of the plate component fully located in the frame portion with an alternate standard adhesive film seal in a fully installed position with a portion shown in section and a magnified portion thereof; Figure 59 is a top plan view of the plate component fully located in the frame portion with an alternate standard adhesive film seal in a fully installed position with a portion shown in section and a magnified portion thereof; Figure 60 is a side view of a Prior Art plate after thermo cycling illustrating the effects warpage and shrinkage which occur in Prior Art microplates; Figure 61 is a front view of the plate component with a magnified portion providing typical dimensions; Figure 62 is a side view of the plate component with a magnified portion providing typical dimensions; and Figure 63 is a top view of the plate component with two magnified portions providing typical dimensions.

Detailed Description

Figures 1 to 5 illustrate the frame component 10. The frame component 10 has a deck portion 12, a frame portion 14 and a skirt portion 16 connecting the deck portion 12 to the frame portion 14. The skirt portion 16 is provided with a number of apertures 18 to assist in the robotic handling of the microplate as a whole. The deck portion 12 is provided with grid notation in the form of letters 20 and numbers 22. The grid notation allows for recordal of the particular wells. The front and back edges of the deck portion 12 and the skirt portion 16 are scalloped 24. The scalloping enables the plate component 30 to be easily removed from the frame component 10 as the plate component 30 overhangs the frame component at those scallop points 24. This is discussed in more detail later in combination with the plate component 30. The deck portion 12 is also provided with a plurality of apertures 26 for receiving the wells 32 of the plate component 30. The apertures 26 form a tight friction fit with the wells 32 of the plate component. The frame component 10 also has its bottom left corner cut 28 as is standard with the majority of microplates in order to assist with orientation on robotic liquid handling robots or the thermal cyclers themselves. The frame component is formed from a plastics material, suitable plastics materials include polycarbonate, acrylic, polyamides, filled polypropylene and cyclin olefin copolymers. The preferred plastics material is CD/DVD carbonate.

Figures 6 to 10 and 61 to 63 illustrate the plate component 30. The plate component 30 has a plurality of wells 32. The wells 32 are connected together in a first direcfion by a plurality of connecting arms 34 to form strips 36 with a tab 38, 40 located on either end.

The wells 32 and thus the strips 36 are also connected together in a second perpendicular direction by a plurality of connecting tear points 42 to form the plate component 30. The wells 32 are arranged in the plate component 30 such that they are in the same locations as the apertures 26 in the frame component. In this way, when the plate component 30 is located above the frame component 10 the wells 32 line up with the apertures 26, as can be seen in Figure 11. This means that when the plate component 30 is brought down on to the frame component 10, the wells 32 locate within the apertures, as can be seen in Figure 12. An upper portion 44 of each of the wells 32 is adapted to be a friction fit with each of the apertures 26 such that the plate component 30 remains in position in the frame component 10 until its removal is desired by the user. The plate component is formed from a plastics material, suitable plastics materials include polypropylene (homo or co-polymer), high or medium density polyethylene, polystyrene or cyclin olefin copolymers. The preferred plastics material is polypropylene as a homo polymer. The plate component may be formed from the same plastics material as the frame component in one alternative. In another alternative the plate may be formed from a different plastics material to the frame component.

Figures 19 to 23 show the plate component 30 in situ in the frame component 10. The tabs 38, 40 assist in the removal of the plate component 30 from the frame component 10, in conjunction with the scallops 24. The tab 40 may have printed notation 46 to indicate which strip 36 it is.

Each well 32 is connected to another well 32 in its strip 30 by means of two connecting arms 34. The connecting arms 34 are curved and thus are longer than the actual distance between the wells 32, as can be seen in Figure 13. The connecting arms 34 preferably have a width of about 0.5mm and a depth of about 0.75mm. The curvature of the arms means that if the plastics material contracts or expands, the arms simply straighten or curve further if the well 32 itself is retained rigidly in a fixed position. This means that when the plate component 30 is located in the frame component 10 once the assembly undergoes thermal cycling any expansion/contraction in the plastics material of the plate component 30 simply results in a shortening/lengthening of the connecting arms 34 through the arms straightening or becoming more curved without any effect being felt by the well 32 itself. The well 32 itself remains in exactly the same position throughout the full thermal cycling process.

The strips 36 are connected to each other by connecting tear points 42, which can also be seen in Figure 13. The connecting tear points 42 are essentially formed of two small triangles 48 which have one edge of each of the triangles connected to the respective wells 32 and which have the opposing points of each of the triangles connected together such that the connecting tear points 42 resembles the shape of a diablo. The tear points 42 are preferably about 0.26mm wide and have a depth of about 0.1mm at the point where the tear points 42 are separable. The centre of the diablo where the points of the two triangles are connected is the weak point of the connecting tear points 42 and as such when the strip labelled Al for example is moved relative to the strip labelled A2 the strips separate from each other about the weak point as can be seen in Figure 14. Figure 14 shows the mechanism of the separation of the strips and Figures 15 and 16 show a single strip completely separated, and a block of 3 strips completely separated respectively. Once the separation has been completed, be it a single strip or a block of strips, the same amount of material remains connected to each well in the form of a small triangle 48. This can be seen more clearly in Figure 17 which shows the edge of the plate 30 from which a strip has been separated, and a small triangle 48 remaining connecting to each well which corresponds to one half of the diablo. Because the triangles 48 which remain connected are so small and because the connecting tear points 42 separate into 2 substantially equally sized portions when separated any strip or block of strips can be placed next to each other in the frame portion without the triangles 48 connected to the respective separated strips interacting with each other. Furthermore, as with the connecting arms 34, the connecting tear points 42 are adapted to expand/contract as the assembly undergoes thermal cycling such that the well 32 itself remains in exactly the same position throughout the full thermal cycling process.

Figures 24 to 29 illustrate the cap mat 50. The cap mat 50 has a plurality of caps 52. The caps 52 are connected together in a first direction by a plurality of connecting arms 54 to form strips 56 with a tab 58, 60 located on either end. The caps 52 and thus the strips 56 are also connected together in a second perpendicular direction by a plurality of connecting tear points 62 to form the cap mat 50. The caps 52 are arranged in the cap mat 50 such that they are in the same locations as the wells 32 in the plate component 30 and thus the apertures 26 in the frame component 10. In this way, when the cap mat 50 is located above the plate component 30 (whether or not it is installed into the frame component 10) the caps 52 line up with the wells 32 and are readily located thereon to seal the wells 32 as can be seen in Figure 35. A lower portion 64 of each of the caps 52 is adapted to be a friction fit with each of the wells 32 such that the cap mat 50 remains in position sealing the wells 32 of the plate component 30 unit its removal is desired by the user.

The caps themselves may be domed or flat and may be optically clear or optically transparent as applicable for the relevant application.

Figures 36 to 41 show the cap mat 50 in situ sealing the wells 32 of the plate component 30. The tabs 58, 60 assist in the removal of the cap mat 50 from the plate component 30.

The tabs 58, 60 of the cap mat 50 are smaller than the tabs 38, 40 of the plate component 30. The tabs 58, 60 of the cap mat 50 are also provided with spacers 66, 68 which keep the tabs 58, 60 of the cap mat 50 spaced apart from the tabs 38, 40 of the plate component 30.

Figures 42 to 47 show the cap mat 50 in situ sealing the wells 32 of the plate component 30, whilst the plate component 30 is installed in the frame component 10.

Each cap 52 is connected to another cap 52 in its strip 56 by means of two connecting arms 54. The connecting arms 54 are curved and thus are longer than the actual distance between the tabs 52 as can be seen in Figures 30 and 31. The connecting arms 54 preferably have a width of about 0.5mm and a depth of about 0.75mm. The curvature of the arms means that if the plastics material contracts or expands, the arms simply straighten or curve further if the cap 52 itself is retained rigidly in a fixed position. This means that when the cap mat 50 is located in position on the plate component 30 and the plate component is located in the frame component 10 once the assembly undergoes thermal cycling any expansion/contraction in the plastics material of the cap mat 50 simply results in a shortening/lengthening of the connecting arms 54 through the arms straightening or becoming more curved without any effect being felt by the cap 52 itself.

The cap 52 itself remains in exactly the same position throughout the full thermal cycling process.

The strips 56 are connected to each other by connecting tear points 62, which can also be seen in Figures 30 and 31. The connecting tear points 62 are essentially formed of two small trIangles 70 which have one edge of each of the trIangles connected to the respective caps 52 and which have the opposing points of each of the triangles connected together such that the connecting tear points 62 resembles the shape of a diablo. The tear points 62 are preferably about 0.26mm wide and have a depth of about 0.1mm at the point where the tear points 62 are separable. The centre of the diablo where the points of the two triangles are connected is the weak point of the connecting tear points 62 and as such when a first strip for example is moved relative to a second strip the strips separate from each other about the weak point. Furthermore, as with the connecting arms 54, the connecting tear points 62 are adapted to expand/contract as the assembly undergoes thermal cycling such that the cap 52 itself remains in exactly the same position throughout the full thermal cycling process.

The cap mat may be arranged as shown in the Figures 30, 32 and 33 and be adapted to be separable into strips of 8 caps or in an alternative the connecting arms and connecting tear points can be changed such that the cap mat is adapted to be separable into strip of 12 caps.

Figures 32 and 33 show a single strip completely separated, and a block of 3 strips completely separated respectively. Once the separation has been completed, be it a single strip or a block of strips, the same amount of material remains connected to each well in the form of the small triangle 70. Because the triangles 70 which remain connected are so small and because the connecting tear points 62 separate into 2 equally sized portions when torn, any strip or block of strips can be placed next to each other in the plate portion 30 without the triangles 70 connected to the respective torn strips interacting with each other.

Figure 48 illustrates that the plate component 30 strips or blocks once separated and the cap mat 50 strips or blocks once separated can be placed independently into the frame component 10.

Figures 49 to 53 illustrate that the plate component 30 strips or blocks once separated and the cap mat 50 strips or blocks once separated can be used independently of the frame component 10 if desired.

Figures 54 and 55 illustrate that the cap mat 50 can be used in conjunction with alternate plates other than the plate component 30/ frame component 10 combination previously described such as standard semi-skirted 72 and full-skirted 74 PCR plates.

Figures 56 to 59 illustrate that the plate component 30 /frame component 10 combination previously described can also be used in combination with a traditional adhesive sealing mat 76 instead of the cap mat 50 previously described.

Claims (1)

1. <claim-text>Claims: 1. A plate component for PCF1 reactions, comprising a plurality of discrete wells arranged in an array, wherein each well in the array is connected to another well in the array in a first direction by a connecting arm and in a second direction by a connecting tear point.</claim-text> <claim-text>2. A plate component as claimed in claim 1 wherein the connecting arm is longer than the distance between the wells.</claim-text> <claim-text>3. A plate component as claimed in claim 2 wherein the connecting arm is curved.</claim-text> <claim-text>4. A plate component as claimed in claim 3 wherein the curvature of the connecting arm is adapted to change under thermal cycling conditions such that the distance between the wells remains unchanged.</claim-text> <claim-text>5. A plate component as claimed in any preceding claim wherein each well in the array is connected to another well in the array in a first direction by two connecting arms.</claim-text> <claim-text>6. A plate component as claimed in any preceding claim wherein the wells are connected together in the first direction by a connecting arm to form a strip.</claim-text> <claim-text>7. A plate component as claimed in claim 6 wherein each strip of wells is separable from the plate component by means of the connecting tear point.</claim-text> <claim-text>8. A plate component as claimed in claim 7 wherein the connecting tear point is adapted to separate into two equally sized portions during separation an equally sized portion remaining connected to each strip.</claim-text> <claim-text>9. A cap mat for sealing wells in PCR reactions, comprising a plurality of discrete caps arranged in an array, wherein each cap in the array is connected to another cap in the array in a first direction by a connecting arm and in a second direction by a connecting tear point.</claim-text> <claim-text>10. A cap mat as claimed in claim 9 wherein the connecting arm is longer than the distance between the caps.</claim-text> <claim-text>11. A cap mat as claimed in claim 10 wherein the connecting arm is curved.</claim-text> <claim-text>12. A cap mat as claimed in claim 11 wherein the curvature of the connecting arm is adapted to change under thermal cycling conditions such that the distance between the caps remains unchanged.</claim-text> <claim-text>13. A cap mat as claimed in any preceding claim wherein each cap in the array is connected to another cap in the array in a first direction by two connecting arms.</claim-text> <claim-text>14. A cap mat as claimed in any of claims 9 to 13 wherein the caps are connected together in the first direction by a connecting arm to form a strip.</claim-text> <claim-text>15. A plate component as claimed in claim 14 wherein each strip of caps is separable from the cap mat by means of the connecting tear point.</claim-text> <claim-text>16. A cap mat as claimed in claim 15 wherein the connecting tear point is adapted to separate into two equally sized portions during separation an equally sized portion remaining connected to each strip.</claim-text> <claim-text>17. A multi-well plate assembly for use in PCR reaction comprising a plate component as claimed in any of claims 1 to 8 and a frame component wherein the frame component is adapted to support the plate component.</claim-text> <claim-text>18. A multi-well plate assembly as claimed in claim 17 wherein the frame component comprises a deck portion, a skirt portion and a frame portion.</claim-text> <claim-text>19. A multi-well plate assembly as claimed in claim 18 wherein the deck portion comprises a plurality of apertures each aperture being adapted to receive and retain a well of the plate component or separated strip or block of strips thereof.</claim-text> <claim-text>20. A plate component for use in PCR reactions, substantially as herein described with reference to and as illustrated in any combination of Figures ito 63.</claim-text> <claim-text>21. A cap mat for sealing wells in PCR reactions, substantially as herein described with reference to and as illustrated in any combination of Figures 1 to 63.</claim-text> <claim-text>22. A multi-well plate assembly for use in PCR reactions, substantially as herein described with reference to and as illustrated in any combination of Figures 1 to 63.</claim-text>