GB2511692A

GB2511692A - An apparatus for treating a test sample

Info

Publication number: GB2511692A
Application number: GB1410839.3A
Authority: GB
Inventors: Jonathan Theobold
Original assignee: Bibby Scientific Ltd
Current assignee: Bibby Scientific Ltd
Priority date: 2009-08-08
Filing date: 2009-08-08
Publication date: 2014-09-10
Also published as: GB0913854D0; GB201410839D0; GB2472454B; GB201410840D0; GB2472454A; GB2511693A

Abstract

An apparatus 10 for treating a test sample includes a housing 11a having an upper and a lower surface; a support member 13 for supporting one or more sample containers 30, said support member being laterally moveable between a deployed and an operative condition; and a heatable member 23 for effecting heating of an upper part of the one or more test sample container, wherein the upper surface of the housing is configured to engage and support the lower surface of a like apparatus, such that two or more apparatus can be stacked on top of each other. The apparatus is used to amplify segments of DNA using the Polymerase Chain Reaction (PCR).

Description

Title: An apparatus for treating a test sample Descriøtion of Invention This invention relates to an apparatus for treating a test sample.

More particularly, but not exclusively, this invention relates to an apparatus for amplifying (i.e. creating duplicate copies of) segments of DNA using the Polymerase Chain Reaction (PCR). Such apparatus are often referred to in the art as thermal cyclers', PCR Machines' or DNA Amplifiers'. These apparatus expose test samples to a thermal cycle (by raising and lowering the temperature) over a predetermined period of time, which gives rise to duplicate copies of the DNA segment.

Known prior art apparatus of this kind include a support member for supporting one or more test sample containers. The support member has a plurality of recesses shaped to receive a number of test sample containers. Typically the containers (and the recesses in the support member which receive them) are conical. It is known for the support member to be slidably moveable between a deployed condition and a (stored) operative condition. In the operative condition the support member is positioned inside a housing. The user can slide the support member to the deployed condition so that test samples can be inserted into the recesses in the support member, and then slide the support to the operative condition so that the samples can be treated.

The prior art apparatus also includes a temperature change member for effecting cooling and/or heating of the test sample containers. Typically, the temperature change member is provided in the form of a Peltier element (advantageously used because its temperature can be changed, substantially, over a very short time period), which is positioned beneath the support member. The prior art apparatus also includes a heat plate or the like which is moved into engagement with lids covering the open ends of the test sample containers, prior to the heating/cooling cycle, to prevent the mixture therein condensing on the inside of the lids. In the prior art apparatus, the heat plate is moved into engagement with the lids covering the open ends of the test sample containers after the support member has been moved to the (stored) operative condition, and the movement of the heat plate is effected by an electric motor. In an alternative prior art apparatus, the heat plate is maintained stationary with the sample containers being moved, by an electric motor, into engagement with the heat plate. In a further alternative prior art apparatus the heat plate is provided on a pivotable lid which is pivoted downwardly manually by a user until the heat plate engages the lids of the sample containers. The lid is held in place by a threaded mechanism which is tightened manually by the user so as to provide a required downward force to the lids of the sample containers.

A disadvantage with the prior art apparatus is the automated movement of the heat plate to engage the container lids. If the electric motor fails, or if power to the apparatus is temporarily cut off, it is not possible (or it is extremely difficult) for a user to withdraw the samples from the device. This can result in the samples becoming irreversibly damaged, and thus potentially useless, which can have disastrous consequences if the samples being treated are the only ones available (e.g. if the DNA is evidence in relation to a criminal investigation). A further disadvantage with the prior art apparatus, particularly those with a pivotable lid, is that two apparatus cannot be stacked on top of each other, thus taking up more work top space than desirable. A further disadvantage with the prior art, again particularly those with a pivotable lid, is that they do not include a means for ensuring that the downward force applied by the heat plate is of a preferred magnitude. They can easily be over- tightened, which can result in damage to the sample containers, or under-tightened, thus not sealing the sample container lids adequately.

The present invention has been devised to address these problems.

According to a first aspect of the invention we provide an apparatus for treating a test sample including:-a support member for supporting one or more test sample containers, said support member being moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, wherein in the course of movement of the support member from the deployed condition to the operative condition the heatable member is caused to move into engagement with an upper part of the one or more test sample containers.

According to a second aspect of the invention we provide an apparatus for treating a test sample including:-a housing; a carrier member moveably supported relative to the housing; a support member for supporting one or more test sample containers, said support member being moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, wherein the heatable member is moveably supported on the carrier member.

According to a third aspect of the invention we provide an apparatus for treating a test sample including:-a support member for supporting one or more test sample containers, said support member being moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, the heatable member being moveable into engagement with an upper part of the one or more test sample containers, wherein the heatable member is configured to apply a predetermined force to the upper part of the one or more test sample containers, when the containers selected have a height within a predetermined range.

According to a fourth aspect of the invention we provide an apparatus for treating a test sample including:-a support member for supporting one or more test sample containers, said support member being moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, the heatable member being moveable into engagement with an upper part of the one or more test sample containers, wherein the heatable member is configured to apply a predetermined force to the upper part of the one or more test sample containers, when the distance from a surface of the heatable member to a top of the container(s) is within a predetermined range.

According to a fifth aspect of the invention we provide an apparatus for treating a test sample including:-a housing having an upper surface and a lower surface; a support member for supporting one or more test sample containers, said support member being laterally moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, wherein the upper surface of the housing is configured to engage and support the lower surface of a like apparatus, such that two or more apparatus can be stacked on top of each other.

Further features of the first, second, third, fourth and fifth aspects of the invention are set forth in the dependent clauses appended hereto.

Examples of the invention will now be described by way of example only with reference to the accompanying drawings, of which:-Figure 1 is a perspective view of a first embodiment of an apparatus in accordance with the present invention in a operative condition; Figure 2 is a perspective view of the apparatus of figure 1 with a support member thereof shown in a deployed condition; Figure 3 is a side view of the apparatus of figure 1; Figure 4 is a perspective view of a second embodiment of an apparatus in accordance with the present invention in a operative condition; Figure 5 is a side view of the apparatus of figure 4; Figure 6 is a perspective view of a plurality of apparatus, in a nested configuration, each apparatus being in accordance with the present invention; Figure 7 is a perspective view of the working components of an apparatus in accordance with the present invention in a deployed condition; Figure 8 is a perspective view of the working components of an apparatus in accordance with the present invention in subsequent position, with the support member thereof having been moved towards its operative condition; Figure 9 is a perspective view of the working components of an apparatus in accordance with the present invention in a yet subsequent position, with the support member thereof having been moved further towards its operative condition; Figure 10 is a perspective view of the working components of an apparatus in accordance with the present invention in an operative condition; Figure 11 is a side sectional view of the working components of an apparatus in accordance with the present invention in a deployed condition; Figure 12 is a side sectional view of the working components of an apparatus in accordance with the present invention in subsequent position, with the support member thereof having been moved partially towards its operative condition; Figure 13 is a side sectional view of the working components of an apparatus in accordance with the present invention in a yet subsequent position, with the support member thereof having been moved further towards its operative condition; Figure 14 is a side sectional view of the working components of an apparatus in accordance with the present invention in an operative condition; Figure 15 is a further side view of the working components of an apparatus in accordance with the present invention in the deployed condition; Figure 16 is a graph showing the relationship between the height of a test sample container used and the resulting vertical force applied by the heatable member to the upper parts of the containers; Figure 17 is a side sectional view of rear component parts of the apparatus; Figure 18 is a perspective view of rear component parts of the apparatus; and Figure 19 is a perspective view of front component parts of the apparatus; Figure 20 is a further perspective view of front component parts of the apparatus; Figure 21 is a further perspective view of rear component parts of the apparatus; Figure 22 is a further side sectional view of rear component parts of the apparatus; and Figure 23 is a graph showing the relationship between the height of a test sample container used and the resulting vertical force applied by the heatable member to the upper parts of the containers, in an alternative embodiment.

Referring to figures 1 to 6 these show first 10 and second 110 embodiments of an apparatus in accordance with the present invention. In this example, the apparatus 10, 110 are configured for amplifying (i.e. creating duplicate copies of) segments of DNA using the Polymerase Chain Reaction (PCR). Such apparatus are often referred to in the art as thermal cyclers', PCR Machines' or DNA Amplifiers'. The apparatus 10, 110 expose test samples to a thermal cycle (by raising and lowering the temperature) over a predetermined period of time, which gives rise to duplicate copies of the DNA segment. FOR reactions are more common, but the apparatus can be used for other reactions.

Each apparatus 10, 110 includes a housing 11, 111 which houses the working components of the apparatus 10, 110 (referred to in more detail later and shown in figure 7 to 22. Each apparatus 10, 110 also includes a slidably moveable drawer or support member 13, 113 for supporting a plurality of test sample containers (discussed in more detail below). Figure 2 shows the drawer 13 in a fully deployed condition -where test sample containers can be loaded/unloaded by a user.

The apparatus 10 is a master' apparatus and thus includes a control panel 12 (and control functionality) by which a user can control operation of the apparatus 10. The apparatus 110 is a slave' apparatus in that it has no control panel by which a user can control operation of the apparatus 110.

Each slave' must, instead, be controlled via the master' apparatus 10 (or a computer, e.g. a PC). Providing a master' and one or more slave' apparatus 10, 110 means that a user can simultaneously control a plurality of apparatus 10, 110, thus permitting the user to treat a great number of samples synchronously. The apparatus 10, 110 may be nested or stacked on top of each other (an example of which is shown in figure 6). To facilitate this, an upper surface of the housing is configured to engage and support the lower surface of a like apparatus, such that two or more apparatus can be stacked on top of each other. Each slave' apparatus 110 being connected directly, or indirectly via another slave' apparatus 110, to the master' apparatus 10 to permit control and monitoring signals to pass between the apparatus 10, 110.

The working components of the master' apparatus 10 and the slave' apparatus 110 are identical, and thus only the working components of the master' apparatus 10 will be discussed in detail herein. Thus, referring to figures 7 to 22, these show the mechanical working components of the apparatus 10 in various conditions of operation. None of the electronics are shown, for clarity.

The working components include a housing part 11 a, which provides a main support for the movable components of the apparatus 10. The housing part ii a is substantially n-shaped when viewed from the front of the apparatus 10.

In other words, the housing part 11 a has a central wall 11 b which is generally horizontal, and two, generally L-shaped (in side view), downwardly extending side walls 11 c, lid, each of which is generally vertical. The side walls 11 c, lid define an opening into and out of which some of the movable components of the apparatus 10 can move.

The apparatus 10 includes a carrier member 14, which is also substantially n-shaped when viewed from the front of the apparatus 10. In other words, the carrier member 14 has a central wall 14a which is generally horizontal, and two downwardly extending side walls 14b, 14c, each of which is generally vertical. The side walls 14b, 14c are spaced farther apart than the side walls ii c, lid. The carrier member 14 is pivotally connected to the housing part 11 a by a plurality of connection members 15 (discussed later) such that the carrier member 14 is positioned generally towards the front end of the housing part ii a. Portions of the side walls ii c, lid of the housing ii a positioned towards the front of the apparatus 10 are received in between the side walls 1 4b, 1 4c. Connected to the inwardly facing surface of each side wall 1 4b, 1 4c is a bushing 14d. Each bushing 14d is sandwiched between its respective side wall 1 4b, 1 4c and the side walls ii c, lid of the housing part ii a. The bushings 14d ensure that the carrier member 14, when it moves (discussed later) is maintained in alignment with the housing part ii a.

The apparatus 10 includes four connection members 15, two provided at each side of the housing part ii a. The connection members 15 are configured to provide a parallel motion linkage (as is well known in the art) between the housing part 11 a and the carrier member 14. In other words, each connection member 15 is pivotally connected at one, upper, end 16 to the housing part 11 a and pivotally connected at its opposite, lower, end 17 to the carrier member 14. The axes of the pivotal connections 16, 17 of the connection members 15 to the housing 11 a and to the carrier member 14 are generally horizontal. The pivotal connection 17 at the lower end of each connection member 15 includes a part 17a which is moveable along an arcuate aperture 1 7b provided in the respective side wall 11 c, lid of the housing part 11 a. The apertures i7b thus act as guides for the lower ends of the connection members 15. In more detail, with reference to figure 19, the part 17a (at least the part i7a provided on the foremost connection members 15) has two parts which are biased towards each other by a spring 17d, thus frictionally engaging the side walls 11 c, 11 d of the housing part 11 a. This frictional engagement improves the feel' to a user when moving the support member 13 between the deployed and operative conditions.

Thus, with the connection members 15 being generally of identical, or substantially identical, length and being parallel with each other (and with the distance between the pivotal connections 16, 17 being substantially identical), the connection members 15 permit the carrier member 14 to move arcuately relative to the housing part 11 a, whilst ensuring that the carrier member 14 remains in a fixed orientation relative to the housing part 11 a during its arcuate movement. In other words, the central wall 14a of the carrier member 14 will remain substantially horizontal during arcuate movement of the carrier member 14 about the connection members 15.

The apparatus 10 also includes a beatable member 23 for effecting heating of the upper parts (e.g. lids) of the test sample containers 30, when the working components of the apparatus 10 are in an operative condition. The heatable member 23 also acts to holds the lids of the containers 30 in place, and also provides a sealing effect if foil seals are used to close the tops of the containers. The heatable member 23 is moveably supported on the carrier member 14, and in this example the heatable member 23 is slidably supported on the carrier member 14.

In more detail, the heatable member 23 is supported on the underside of a generally n-shaped part 24 via four springs 38, which bias the heatable member 23 away from the part 24. The springs 38 provide for automatic levelling of the heatable member 23 relative to the sample containers lids. The springs 38 therefore ensure that the downward force applied by the heatable member 23 is distributed substantially evenly across all of the sample container lids.

Connected to an outwardly facing surface of each generally downwardly extending side wall 24a of the part 24 is a runner 25. Each runner 25 is slidably supported in a respective track 26 -the tracks 26 being connected to inwardly facing surfaces of the side walls 14b, 14c of the carrier member 14.

Thus, the tracks 25 and runners 26 provide for a smooth slidable connection between the heatable member 23 and the carrier member 14, thus permitting the heatable member 23 to slide in a generally horizontal plane. A forwardly facing region of the carrier member 14 includes a downwardly extending lip 14f which is configured to engage in an opening 24b in the part 24. The lip 14f acts so as to limit sliding movement of the part 24 forwardly relative to the carrier member 14.

The heatable member 23 is heated by an electrically powered resistive element contained in a silicon mat adhered to a side of the heatable member 23 opposite the side which engages the container lids.

As discussed previously, the apparatus 10 also includes a slidably moveable drawer or support member 13 for supporting a plurality of test sample containers. In this example, the support member 13 is slidably supported relative to the housing part 11 a. In more detail, the support member 13 has as pair of tracks 19, one connected to each side thereof. Each track 19 slidably supports a respective runner 21 -the runners 21 being connected to inwardly facing surfaces of the side walls 11 c, lid of the housing part 11 a. Thus, the tracks 19 and runners 21 provide for a smooth slidable connection between the support member 13 and the housing part 11 a, thus permitting the support member 13 to slide in a generally horizontal plane. The support member 13 and the heatable member 23 are therefore slidable in planes which are generally parallel to each other.

As can be seen from the figures, the support member 13 includes a part 27 for supporting a plurality of test sample containers 30 (see figure 11). The part 27 includes a plurality of recesses 28, each of which is shaped to receive a test sample container 30. In this example the recesses 28 are conical in shape, and have thus been configured to receive conically shaped test containers 30.

It should be appreciated, however, that the recesses 28 could be any desired shape so long as they provide adequate support for and thermal contact with a chosen shape of test container.

Connected to an underside of the part 27, and in thermal conduction therewith, is a temperature change member 29 for effecting cooling and/or heating of the test sample containers 30. In this example the temperature change member 29 is a thermo electric cooler (e.g. a Peltier element). Connected to an under side of the Peltier element 29 is a heat sink 31 including a plurality of fins which are aligned with each other. The heat sink 31 may be force air cooled by a fan (not shown). The purpose of the heat sink 31 is to dissipate energy away from the underside of the Peltier element 31 so as to maintain the underside of the Peltier element 29 at a temperature which is as close as possible to ambient temperature. This permits the Peltier element 29 to be as efficient as possible when cyclically heating and cooling the test containers 30.

The support member 13 is also provided with a pair of camming members 35.

Each camming member 35 is supported by a generally triangular part 36 which is connected to an innermost end of the support member 13. Each camming member 35 is generally elongate and extends upwardly towards the central wall 11 b of the housing 11 a. An upper forwardly facing surface of each camming member 35 is provided with a gradual radius to improve its camming action. The camming members 35 slide with the support member 13 when the latter is moved.

Each camming member 35 is positioned such that it is engageable with a camming surface 37 provided on the part 24 supporting the heatable member 23. The camming member 35 effects pivoting of the carrier member 14 upwardly, away from the housing 11 a, when the support member 13 is moved towards its deployed condition. An upwardly facing surface 35a of the camming members 35 is also configured to engage and slide along an underside of the part 24, thus permitting sliding movement between the support member 13 and the part 24.

A rearwardly facing surface 35b of each camming member 35 is also configured to engage a part 39 of the part 24, such that when the support member 13 reaches a predetermined position when being moved from the deployed to the operative condition, the heatable member 23 is caused to move with the support member 13 towards the operative condition (described in more detail later).

The part 24 supporting the heatable member 23 and the carrier member 14 are connected to each other by a spring 40 which biases the part 24 and the carrier member 14 towards each other. One end of the spring 40 is connected to a formation 41 provided on an upwardly facing surface of the central wall 14a of the carrier member 14 and an opposite end of the spring 40 is connected to the part 24 via an elongate part 42 which extends away from the part 24 towards a rear of the apparatus 10.

The apparatus 10 is also provided with a holding device 50 (shown only in figures 17 and 18) for holding the support member 13 in the operative condition. In this example, the holding device 50 is provided as a latch 51 connected to the housing 11 a via a bracket 53 which latches onto a rearmost portion 52 of the support member 13. The latch 51 automatically holds the support member 13 when the support member 13 is pushed by a user to the operative condition. In order to unlatch the support member 13 a user must push the support member 13 inwardly, slightly past the operative condition. It will be appreciated that other types of holding device could be used.

As will become apparent from the following description, the apparatus 10 is configured such that in the course of movement of the support member 13 from the deployed condition (see figure 2) to the operative condition (see figures 1, 10 and 14) the heatable member 23 is caused to move into engagement with the lids (or seals) of the test sample containers 30. This has the advantage that no motorised movement of the heatable member 23 is required, and that the user only has to manually push the support member or drawer 13 inwardly to its operative condition before treatment of the test samples can commence. The apparatus has also been devised such that the heatable member 23 is configured to apply a predetermined force (substantially 60N in this example) to the upper parts of the test sample containers 30, when the containers 30 selected have a height within a predetermined range. In the present example the height range of the containers used is between 9.6mm and 36mm, but the relevant height is actually that from the top of the Peltier element 29 to the top of the container -it is thus the effective height of the containers once they are supported in the support member 27. Thus, in the present example, this translates to a height range of between 18.5mm and 36.5mm from the top of the Peltier element 29 to the top of the containers. It should be appreciated by those skilled in the art, of course, that the apparatus could be configured to operate with containers of smaller or larger vertical dimension.

The apparatus 10 works as follows. Starting with the apparatus 10 in its deployed condition, i.e. that shown in figures 2, 7 and 11, the user is able to insert test sample containers 30 into the recesses 28 of the part 27. Once these have been correctly inserted, the user pushes the support member 13 towards the housing 11 a, thus sliding the support member 13 horizontally inwardly, with the tracks 21 sliding relative to the runners 19. It should be noted that the apparatus 10 has been configured such that only about 30N force is required to move the support member 13 from its deployed condition to its operative condition. This ensures that almost any user can use the apparatus 10 and also that the user does not have to hold the housing with one hand, whilst pushing the support member 13 with their other hand, to ensure that the apparatus 10 does not move along the surface on which it is supported.

Thus, during a first portion of the course of movement of the support member 13 from the deployed condition to the operative condition (as shown in figures 1, 10 and 14), only the support member 13 is moveable. As the support member 13 moves inwardly, the upwardly facing surface of the camming members 35 slide along the underside of the part 24, until the camming members 35 reach the camming surfaces 37 provided on the part 24. At this point, the heatable member 14 is caused to move gradually downwardly into engagement with the lids of the test sample containers 30, as a result of the camming member 35 moving inwardly relative to the camming surface 37.

The heatable member 23 and its part 24 thus pivot downwardly, under their own weight, as the support member 13 is moved further towards its operative condition (with the connection members 15 pivoting about their connections 16 to the housing part 11 a). This continues until an underside of the heatable member 23 engages the lids (or seals) of the test sample containers 30.

If relatively small (i.e. short in height) containers 30 are used, the part 24 will pivot further downwardly -because the heatable member 23 must move further to engage the lids of the containers 30. Whereas, when the containers used are taller, the part 24 will not pivot as far, and therefore not move as tar downwardly.

The camming members 35 and the camming surfaces 37 are configured such that whilst the heatable member 23 is moving pivotally downwardly, the support member 13 and the beatable member 23 both move horizontally inwardly together at the same rate. The heatable member 23 is therefore automatically correctly aligned with the containers 30, and will only engage the lids of the containers 30 with a downward force. Thus, no shearing forces will be applied to the lids of the containers 30 when the beatable member 23 engages them.

Once the beatable member 23 has engaged the lids of the containers 30, the heatable member 23 moves inwardly together with the support member 13 towards the operative condition, because the rearwardly facing surfaces 35b of the camming members 35 engage the part 39 of the part 24, and move the part 24 rearwardly. However, as the heatable member 23 cannot move downwardly any further, the carrier member 14 is prevented from moving downwardly. Thus, as the support member 13 is continued to be pushed inwardly, the support member 13 and the heatable member 23 slide away from the carrier member 14, thus extending the spring 40. In other words, the part 24 supporting the heatable member 23 slides relative to the carrier member 14, with the runners 25 sliding in a rearward direction along the tracks 26. The user continues to push the support member 13 until the latch 50 has been actuated, thus holding the support member 13 (and the heatable member 23) in the operative condition.

When in the operative condition, the tension in the spring 40 results in a downward force being applied by the heatable member 23 to the lids of the containers 30. This is a result of a component of the force in the spring 40 being translated via the connection members 15 to the carrier member 14 to urge the carrier member 14, and thus the heatable member 23, downwardly.

The magnitude of the vertical force applied by the heatable member 23 to the lids of the containers 23 is dependant on the angle (9) of the connection bars to the vertical, and to the tension in the spring 40. The following equation applies (assuming a perfect, frictionless mechanism):-Force applied by spring = Vertical force applied Tan (9) by the heatable member 23 When the height of the sample container is relatively small/short, e.g. 9.6mm (where the height of the top of the containers from the top of the Peltier element 29 is about 18.5mm), the angle (9) of the connection members 15 to the vertical is relatively small, thus resulting in a relatively small value for Tan (9). This results in a relatively high proportion of the force applied by the spring 40 being translated into a vertical force applied by heatable member 23 to the lids of the containers 30.

Conversely, when the height of the sample container is relatively large/tall, e.g. 36mm (where the height of the top of the containers from the top of the Peltier element 29 is about 36.5mm) the angle (9) of the connection members 15 to the vertical is relatively large, thus resulting in a relatively large value for Tan (9). This results in a relatively low proportion of the force applied by the spring 40 being translated into a vertical force applied by heatable member 23 to the lids of the containers 30.

However, the force applied by the spring 40 is dependant upon the length of extension thereof. When the container 30 used is relatively small/short, the spring 40 is not extended as far as when the containers 30 are relatively large/tall (because the relative movement between the part 24 and the carrier member 14 is relatively small). Thus, for small/short containers, a reduced tension in the spring 40 is countered by a small angle (6) of the connection members 15 to the vertical, and, for tall containers 30, an increased tension in the spring 40 is countered by an increased angle (6) of the connection members 15 to the vertical.

The overall effect of this is that, for the present example, the apparatus is configured such that the heatable member 23 applies a predetermined force (substantially 60N in this example) to the lids of the test sample containers 30, when the containers 30 selected have a height within a predetermined range, which in this example is 9.6mm to 36mm (or between 18.5mm and 36.5mm from the top of the Peltier element 29 to the top of the container). In other words, so long as the containers 30 used are within this range, the heatable member 23 is advantageously configured to apply a substantially uniform force to the lids of the containers 30. Figure 16 is a graph showing the relationship between the height of the container 30 used and the resulting vertical force applied by the heatable member 23 to the upper parts of the containers 30. It can be seen from this graph that even when the height of the test sample containers differs by 17mm, the force applied by the heatable member 23 is calculated to be substantially the same (about 60N), and only varies by around 1 N across that range of container heights. This substantially uniform force of 60N is achieved by selecting a spring with an appropriate spring constant / rating.

It should be noted that one advantage of the apparatus 10 is that the downward force applied by the heatable member 23 is greater than the force required to move the support member 13 to its operative condition. It should also be noted that the downward force could be increased or decreased by increasing or decreasing the stiffness of the spring 40 or by reducing the angle () when the support member 13 is in the operative condition.

Once in the operative condition, the user can activate the Peltier element 29 via the control panel 12 so as to treat the samples in the test containers 30.

In order to move the support member 13 from the operative condition to the deployed condition, the user must push the support member 13 further inwardly so as to disengage the latch 50. The support member 13 is then biased partially outwardly by the spring 40 until the opening 24b in the part 24 engages the part 14f of the carrier member 14, thus preventing any further relative horizontal movement between the part 24 and the carrier member 14.

The user then pulls the support member 13 outwardly, which causes the camming members 35 to engage the camming surfaces 37 thus causing the carrier member 14, and the part 24, to pivot upwardly, which disengages the heatable member 23 from the lids of the containers 30. The heatable member 14 is caused to move gradually upwardly out of engagement with the upper parts of the test sample containers 30. The support member 13 can therefore be slid fully outwardly along the runners 19 until it reaches its deployed condition, with the upper surfaces 35a of the camming members 35 providing sliding support for the part 24. When in the deployed condition, the user can remove the containers 30 and, if desired, insert a further set of test sample containers for treatment.

The calculation of the spring rating I constant for a given embodiment of an apparatus in accordance with the present invention (where the required vertical downward force on the shortest and tallest sample containers is known) can be defined as follows, where: L is working length of the connecting member (15) (i.e. the distance between the pivotal connections 16 and 17); 8 is the angle of the connecting members (15) to the vertical when the support member (13) is in the operative condition and containing the tallest sample containers; 0 is the angle of the connecting members (15) to the vertical when the support member (13) is in the operative condition and containing the shortest sample containers; AD, is the difference between the tallest and shortest sample container (i.e. the vertical displacement between them); AD17 is the difference between the horizontal displacement of the carrier member (14) when the support member (13) is in the operative condition and containing the tallest sample containers, and when the support member (13) is in the operative condition and containing the shortest sample containers; 1: is the vertical, downward, force applied by the heatable member (23) to the tallest sample containers; F is the vertical, downward, force applied by the heatable member (23) to the shortest sample containers; F. is the force applied by the spring (40) when the support member (13) is in the operative condition and containing the tallest sample containers; F5' is the force applied by the spring when the support member (13) is in the operative condition and containing the shortest sample containers; and k is the spring constant! rating.

Given L, 8, AL), F and Fr': (LcosO+z\D, O=arccos I K L) = F tan 8, F.= f,tan8', ADh =L(sin8_sin8) and k ADh For the embodiment as discussed above (and as shown in the graph in figure 16), and as shown in the figures, where the vertical, downward, force applied by the heatable member 23 to the sample containers is desired to be a substantially uniform 60N for the tallest through to the shortest containers: Let L = 265.6mm, 8 = 30°, AD1, = 22mm and F = F1,t= 60N, therefore: (LCOSO+ADJ (265.6cos3O+22 O=arccos arccosI =18.4° K L) 265.6) = F tan8 60 tan 30 = 34.64EV F5= F1,tan8'= 60 tanl8.4 = 19.96N ADh = L(sin 8-sin t) = 265.6(sin3o -sinl8.4) = 48.96mm F -F' 34.64-19.96 The spring constant required = k = S = = O.29984N,nm AD,, 48.96 As an alternative, is possible to select an appropriate spring constant / rating in order to reduce the downward force applied by the heatable member 23 as the height of the sample containers increases, and this would require no changes to the mechanism.

The downward force required for the containers is set by the force needed to maintain the integrity of the seal on foil sealed plates used on the short containers. Taller consumables conventionally use caps, rather than toil seals, and tend to require less downward force to maintain the integrity of the seal.

When the spring constant is chosen so as to provide a substantially uniform torce of 60N, the force required by a user to move the support member 13 to its operative condition is greater the taller the containers are (as the spring has to extend further).

Advantageously, with the mechanism of the present invention, it is possible to select a spring with a particular spring constant which has the effect of reducing the force applied by the heatable member 23 to taller containers.

This has the result of reducing the force required by a user to move the support member 13 to its operative condition.

For example, where the vertical, downward, force applied to the sample containers is desired to be 40N for the tallest containers and 60N for the shortest containers: Let L = 265.6mm, 8 = 30°, AD = 22mm, = 40N and E'= 60N, therefore: (Lcos8-f-AD (265.6cos3O+22 8' arccos = arccosl = 18.4° L) 265.6) F5 = F tanG 40 tan 30 = 23.09N F1.'= F'(an8'=60(an18.4= 19.96/V AD,, = L(sin 8-sin 8) = 265.6(sin3o -sinls.4) = 48.96mm The spring constant required = A = F5 -F5' 23.09-19.96 = 0.06393Nmm1 AD,, 48.96 Figure 23 is a graph illustrating this value of spring constant. Figure 23 shows the relationship between the height of the container 30 used and the resulting vertical force applied by the heatable member 23 to the upper parts of the containers 30. It can be seen from this graph that the force gradually increases from 40N (for the tallest containers) to 60N (for the shortest container). Thus, the force applied by the heatable member 23 is inversely proportional to the height of the containers used.

When used in this specification and clauses, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following clauses, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

The following clauses set out features of the inventions described above.

1. An apparatus for treating a test sample including:-a support member for supporting one or more test sample containers, said support member being moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, wherein in the course of movement of the support member from the deployed condition to the operative condition the heatable member is caused to move into engagement with an upper part of the one or more test sample containers.

2. An apparatus according to any preceding clause wherein during a first portion of the course of movement of the support member from the deployed condition to the operative condition, only the support member is moveable.

3. An apparatus according to any preceding clause wherein when the support member reaches a predetermined position between the deployed and operative conditions, the heatable member is caused to move with the support member towards the operative condition.

4. An apparatus according to any preceding clause wherein as the support member is moved towards the operative condition, the heatable member is caused to move gradually downwardly into engagement with the upper part of the one or more test sample containers.

5. An apparatus according to any preceding clause wherein in the course of movement of the support member from the operative condition to the deployed condition the heatable member is caused to move out of engagement with an upper part of the one or more test sample containers.

6. An apparatus according to any preceding clause wherein as the support member is moved away from the operative condition, the heatable member is caused to move gradually upwardly out of engagement with the upper part of the one or more test sample containers.

7. An apparatus according to any preceding clause wherein during a first portion of the course of movement of the support member from the operative condition to the deployed condition, the heatable member is caused to move with the support member towards the deployed condition.

8. An apparatus according to clause 2 wherein when the support member reaches a predetermined position between the operative and deployed conditions, the support member and the heatable member stop moving together, and only the support member is moveable.

9. An apparatus for treating a test sample including:-a housing; a carrier member moveably supported relative to the housing; a support member for supporting one or more test sample containers, said support member being moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, wherein the heatable member is moveably supported on the carrier member.

10. An apparatus according to clause 9 wherein the support member is slidably supported relative to the housing.

11. An apparatus according to 9 or clause 10 wherein the beatable member is slidably supported on the carrier member.

12. An apparatus according to clause 11 as dependant on clause 10 wherein the support member and the heatable member are slideable in planes which are parallel to each other.

13. An apparatus according to any one of clauses 9 to 12 wherein the carrier member is arcuately moveable relative to the housing.

14. An apparatus according to clause 13 wherein the carrier member remains in a fixed orientation relative to the housing during its arcuate movement.

15. An apparatus according to any one of clauses 9 to 14 wherein the carrier member is connected to the housing by a connection member, which connection member is pivotally connected at one end to a part of the housing and pivotally connected at its opposite end to the carrier member.

16. An apparatus according to clause 15 wherein the axes of the pivotal connections of the connection members to the part of the housing and to the carrier member are generally horizontal.

17. An apparatus according to clause 15 wherein the axes of the pivotal connections of the connection member to the part of the housing and to the carrier member are generally parallel to the plane of sliding movement of the support member.

18. An apparatus according to any one of clauses 15 to 17 wherein the apparatus includes a plurality of connection members, at least one connected to respective sides of the carrier member.

19. An apparatus according to clause 14 herein the connection member(s) provide a parallel motion linkage between the housing and the carrier member.

20. An apparatus according to any one of clauses 9 to 19 wherein the heatable member and the carrier member are connected to each other by biasing means which biases said members towards each other.

21. An apparatus according to any one of clauses 9 to 20 wherein movement of the support member towards the operative condition urges the heatable member downwardly into engagement with the upper part of the one or more test sample containers.

22. An apparatus according to clause 21 wherein the downward force applied by the heatable member to the upper part of the one or more test sample containers is between 55N to 65N when the containers selected have a height within a predetermined range.

23. An apparatus according to clause 21 wherein the downward force applied by the heatable member to the upper part of the one or more test sample containers is between 60N to 61 N, when the containers selected have a height within a predetermined range.

24. An apparatus according to clause 21 wherein the downward force applied by the heatable member to the upper part of the one or more test sample containers is substantially 60N, when the containers selected have a height within a predetermined range.

25. An apparatus according to any one of clauses 22 to 24 wherein the predetermined range of the height of the one or more test sample containers selected is between 9.6mm and 36mm.

26. An apparatus according to any preceding clause including a holding device for holding the support member in the operative condition.

27. An apparatus according to clause 25 wherein the holding means includes a latch connected to the housing which engages a portion of the support member.

28. An apparatus for treating a test sample including:-a support member for supporting one or more test sample containers, said support member being moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, the heatable member being moveable into engagement with an upper part of the one or more test sample containers, wherein the heatable member is configured to apply a predetermined force to the upper part of the one or more test sample containers, when the containers selected have a height within a predetermined range.

29. An apparatus according to clause 28 where the predetermined force is substantially uniform when the containers selected have a height within a predetermined range.

30. An apparatus according to clause 28 where the predetermined force is inversely proportional to the height of the containers selected.

31. An apparatus according to clause 28, 29 or 30 wherein the predetermined range of is between 9.6mm and 36mm.

32. An apparatus for treating a test sample including:-a support member for supporting one or more test sample containers, said support member being moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, the heatable member being moveable into engagement with an upper part of the one or more test sample containers, wherein the heatable member is configured to apply a predetermined force to the upper part of the one or more test sample containers, when the distance from a surface of the heatable member to a top of the container(s) is within a predetermined range.

33. An apparatus according to clause 32 where the predetermined force is substantially uniform when the containers selected have a height within a predetermined range.

34. An apparatus according to clause 32 where the predetermined force is inversely proportional to the height of the containers selected.

35. An apparatus according to clause 32, 33 or 34 wherein the predetermined range of is between 18.5mm and 36.5mm.

36. An apparatus for treating a test sample including:-a housing having an upper surface and a lower surface; a support member for supporting one or more test sample containers, said support member being laterally moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, wherein the upper surface of the housing is configured to engage and support the lower surface of a like apparatus, such that two or more apparatus can be stacked on top of each other.

37. An apparatus according to clause 36 wherein the upper surface is substantially planar.

38. An apparatus according to clause 36 or clause 37 wherein the upper surface of the housing includes a projection engageable with a recess in the lower surface of a like apparatus.

39. An apparatus according to clause 36 or clause 37 wherein the lower surface of the housing includes a projection engageable with a recess in the upper surface of a like apparatus.

Claims

CLAIMS1. An apparatus for treating a test sample including:-a housing having an upper surface and a lower surface; a support member for supporting one or more test sample containers, said support member being laterally moveable between a deployed and an operative condition; and a heatable member for effecting heating of an upper part of the one or more test sample containers, wherein the upper surface of the housing is configured to engage and support the lower surface of a like apparatus, such that two or more apparatus can be stacked on top of each other.
2. An apparatus according to claim 1 wherein the upper surface is substantially planar.
3. An apparatus according to claim 1 or claim 2 wherein the upper surface of the housing includes a projection engageable with a recess in the lower surface of a like apparatus.
4. An apparatus according to claim 1 or claim 2 wherein the lower surface of the housing includes a projection engageable with a recess in the upper surface of a like apparatus.
5. An apparatus substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.Al 231 OOBC