FLOW CELL INTERFACE ADAPTOR

A flow cell adaptor for use in cyclic histology, the flow cell adaptor having a body defining a cavity configured to removably receive a flow cell, wherein the adaptor has a fluid input channel configured to direct one or more reagents to a flow cell, and a fluid output channel configured to receive one or more reagents from a flow cell, wherein the flow cell adaptor comprises a heater configured to heat the one or more reagents in the fluid input channel.

The present disclosure relates to a flow cell adaptor for use in cyclic histology, and to a system including a flow cell and a flow cell adaptor.

In immunohistochemistry, and other staining techniques employed in histology, markers are applied to a sample containing a tissue to be analysed. The markers bind with certain target molecules (for example certain genes), and allows the molecules to be imaged.

Typically, only a few target molecules (often less than five) can be imaged at once. However, to perform full analysis of a sample, it may be necessary image hundreds of molecules or more. In order to achieve this, the markers are quenched, flushed from the sample, and new markers are applied for imaging further molecules. This is repeated on a cyclical basis.

In many situations, it is necessary to analyse a large number of tissue samples, imaging hundreds of molecules for each sample. For example, where a large three dimensional tissue sample is to be analysed, and it is desired to obtain information on the three dimensional arrangement of the sample, the sample has to be sliced into thin layers, and each layer analysed separately as independent samples. A number of these larger three dimensional samples may need to be analysed in this way.

According to a first aspect of the invention there is provided a flow cell adaptor for use in cyclic histology, the flow cell adaptor having a body defining a cavity configured to removably receive a flow cell, wherein the adaptor has a fluid input channel configured to direct one or more reagents to a flow cell, and a fluid output channel configured to receive one or more reagents from a flow cell, wherein the flow cell adaptor comprises a heater configured to heat the one or more reagents in the fluid input channel.

The adapter allows for the automation of histology imaging of a large number of samples. The use of the heater to pre-heat reagents before they enter the flow cell ensure the process is efficient and simple to perform. The adapter is simple to construct and use.

The cavity is sized to fit a flow cell which comprises a microscope slide.

The flow cell and an outlet of the fluid input channel and an inlet of the fluid output channel may be biased such that they are urged together.

The body may be formed of two or more parts which may be removably fixed together such that the flow cell can be removed from the cavity.

The adaptor may include a biasing block which may be received at least partially within the cavity. The biasing block may be urged away from a first portion of the body towards the flow cell, which in turn urges the fluid input and output channels and the flow cell together.

The biasing block may incorporate the heater such that the heater heats the block.

At least a portion of the fluid input channel may run through the biasing block to pre-heat the one or more fluids.

At least a portion of the fluid input channel may run adjacent to the biasing block to pre-heat the one or more fluids.

The body may define an opening through which the contents of the flow cell can be imaged.

The body may comprise a ledge configured to support the flow cell.

In use, the flow cell may be supported by the ledge at opposing ends only.

The ledge may be configured to support the flow cell on a first side of the flow cell, and the biasing force may act on a second side of the flow cell, opposite the first side.

A portion of the fluid input channel and a portion of the fluid output channel may both be routed through the ledge.

The flow cell adapter may be sized to fit on a standard histology microscope stage.

The body may define a plurality of cavities. Each cavity may be configured to removably receive a flow cell. The adaptor may have a plurality of fluid input channels, each fluid input channel configured to direct one or more reagents to a respective flow cell. The adaptor may have a plurality of fluid output channels, each fluid output channel configured to receive one or more reagents from a respective flow cell. The flow cell adaptor may comprise one or more heaters configured to heat the one or more reagents in the fluid input channels.

The heater may pre-heat the one or more reagents in the fluid input channel and heat the flow cell.

According to a second aspect of the invention, there is provided a system for performing cyclic histology, the system comprising: a flow cell comprising: a first plate; a second plate; a gasket between the first and second plates, wherein the gasket includes an opening extending therethrough, the opening defined by a perimeter wall, such that an enclosed volume is formed by the first plate, the second plate, and the perimeter wall; and one or more fluid input holes in one of the first plate or the second plate, and one or more fluid output holes in the one of the first plate or the second plate, the one or more fluid input holes and one or more fluid output holes aligned with the enclosed volume, and a flow cell adaptor according to any of the preceding claims wherein the fluid input channel is configured to direct one or more fluids to the one or more fluid input holes, and the fluid output channel is configured to receive one or more fluids from the one or more fluid output holes.

The flow cell can be made using a standard microscope slide and coverslip. The system allows for the automation of histology imaging of a large number of samples. The use of the heater to pre-heat reagents before they enter the flow cell ensure the process is efficient and simple to perform. The system is simple to construct and use.

A single corner of the gasket may be curved.

The first plate or the second plate may be a microscope slide. One of the first plate or the second plate may be a coverslip.

The system may comprise two or more flow cells, wherein the body of the flow cell adaptor defines two or more cavities. Each cavity may be configured to removably receive a flow cell. The adaptor may have one or more fluid input channels configured to direct one or more reagents to the fluid input holes. The adaptor may have one or more fluid output channels configured to receive one or more reagents from the fluid output holes.

According to a third aspect of the invention, there is provided a device for assembling a flow cell comprising a first plate, a second plate, and a gasket between the first plate and the second plate, the device including: a first guide arranged to locate the gasket relative to one of the first plate and second plate, for forming a component part of the flow cell comprising the gasket attached to the one of the first plate and second plate; a second guide arranged to locate the component part of the flow cell relative to the other of the first plate and second plate, for forming the assembled flow cell.

The device makes it easy for a user to accurately and repeatably assemble flow cells.

The device may further include: a third guide arranged to locate the assembled flow cell such that pressure may be applied to the flow cell, to ensure adhesion of the first plate, the second plate, and the gasket.

The third guide may locate the flow cell relative to a planar surface to which pressure is applied, such that the flow cell is substantially flush to the surface.

The first guide and/or the second guide may be inclined relative to a surface on which the device is placed.

The first guide, the second guide, and the third guide where provided, may comprise an edge to locate the first plate, second plate, gasket or component part of the flow cell.

The edge may be formed by a recess extending into a planar surface or a projection extending from the planar surface.

The first guide and/or second guide may comprise both a recess extending into a planar surface, and projections extending from the planar surface, arranged around the recess.

The recess may be arranged to receive a one of the first plate, the second plate, the gasket, or the component part, such that the first plate, the second plate, the gasket, or the component part is substantially flush with the planar surface.

In the first guide, the recess may be arranged to locate the gasket and the projections are arranged to locate the one of the first plate and the second plate relative to the gasket. In the second guide, the recess may be arranged to locate the other of the first plate and the second plate and a first portion of the component part, and the projections are arranged to locate a second portion of the component part.

The recess and corresponding first plate, second plate or gasket may be shaped to only allow placement of the first plate, second plate or gasket in a single orientation.

The recess and the corresponding first plate, second plate or gasket may have a single curved corner.

The edge may be continuous or discontinuous around the perimeter of the flow cell.

The edge may be provided at one or more corners of the perimeter of the flow cell, for example, three corners of the perimeter of the flow cell.

The first guide and/or the second guide may comprise a through hole aligned with the edge of the flow cell.

The first guide, the second guide, and the third guide where provided, may be formed as separate parts.

The first guide, the second guide, and the third guide where provided may be mounted on a common base.

One of the first plate or the second plate may be a microscope slide. One of the first plate or the second plate may be a coverslip.

Features discussed in relation to one aspect of the invention may be applied to any other aspect, unless mutually exclusive.

FIG.1illustrates an example of a flow cell1for use in immunohistochemistry. In the example show, the flow cell1is made using a standard microscope slide3and coverslip5. The microscope slide3is rectangular in shape having length of approximately 75 mm, width of approximately 25 mm and thickness of approximately 1 mm. The coverslip5is also rectangular, have similar or smaller length and width than the microscope slide3and 0.15 mm thick. For example, the coverslip may be 24 mm wide and 50 mm long. The microscope slide3and coverslip5are made of glass and transparent.

A rubber gasket7is provided between the microscope slide3and coverslip5. The gasket7is rectangular in shape having length and width larger than or similar to the coverslip5and smaller than or similar to the microscope slide3. The gasket7is 0.15 mm thick.

An opening9is formed extending through the thickness of the gasket7. In the example shown, the opening9is substantially rectangular in shape, with projections11,13extending at opposing ends along the length of the gasket7. Apertures15,17are formed in the coverslip5, aligned with the projections11,13.

When the flow cell1is assembled, the gasket7is sandwiched between the microscope slide3and coverslip5. Adhesive, or other suitable holding or fixing means may be used to ensure the flow cell1is held together. An enclosed volume19is formed, bounded by a perimeter wall21formed by the edge of the opening9in the gasket7and closed by the microscope slide3and coverslip5on opposite sides. Only the apertures15,17open into the volume19.

In use, a sample may be mounted on the microscope slide3. The flow cell1is then assembled around this, as will be discussed in more detail below, with reference toFIGS.16to19. The gasket7may be placed on the slide before or after the sample. The sample is imaged through the coverslip5.

Reagents23, such as markers23a, or quenching reagents23bare introduce to the flow cell1from reagent reservoirs59a-dthrough a first of the apertures in the coverslip5, forming a fluid input hole15and spent/quenched reagents are removed through the other aperture, forming a fluid output hole17.

An adapter25for mounting a number of flow cells1a,1b1c,1don a standard microscope stage of a histology microscope (not show), will now be described with reference toFIGS.2to8. The adapter25may be provided in the place of the microscope stage insert.

The adapter25has a body27formed of two separate parts29,31-abase portion29and a top portion31. The base portion29is shown inFIG.2.FIGS.3to6and8show the body27of the adapter in an assembled state.FIG.3shows the body in cross-section through a flow cell1, along the length of the flow cell1.FIG.4shows the body in cross-section through the flow cells1a-d, along the width of the flow cells.

The base portion29is rectangular in shape having a length longer than its width and defines four cavities33a,33b,33c,33deach sized to receive a flow cell1a,1b,1c,1d. The cavities33a-dare arranged such that the length of the flow cells1extends across the width of the base portion29.

The cavities33a-dextend through the thickness of the base portion29, to form an opening through which the samples in the flow cells1a-dcan be imaged. As best shown inFIGS.3and8, a ledge35is formed at each end of the cavities33a-d, extending parallel to the length of the base portion29. The ledge35supports the ends of the flow cells1a-dacross their width.

In use, the flow cells1a-dcan be placed in the cavities33a-dfrom above, with the coverslip5facing downwards. As will be discussed below the sample (not shown) is imaged form underneath the base portion29.

The base portion29also includes ports37a,37b,37c,37d,39a,39b,39c,39dat each end of each of the cavities33a-d. Each port37a-d,39a-dis formed in a projection extending upwards from the base portion29, outside the cavities33a-d. The projections are positioned such that they are clear of the microscope stage, in use.

At a first end of each of the cavities33a-dthe corresponding ports37a-dform inlet ports for providing reagents to the flow cells1a-d.

For each cavity, a first conduit41a,41b,41c,41dextends from a reagent reservoir59a-f, and enters through the side of the base portion29at the opposite end of the cavities33a-dto the inlet ports37a-d. The first conduits41a-cextend along the length of the cavities33a-dat the side of the cavity33a-d, beside the flow cells1a-d. The first conduits41a-dexit out of the base portion29adjacent the inlet ports41a-dand then enter the inlet ports41a-d.

The base portion29is formed with a thicker region95at either end of the cavities33a-d. The thicker region95extends the full length of the adapter. The thicker region extends below the flow cells1a-dwhen they are positioned in the cavities. This provides a thinner region97, below the cavities.

The inlet ports37a-dopen into a second conduit43a-d. The second conduit extends through the projection, the thicker region95, and the ledge35. A ferrule (not shown) is provided on the end of the first conduits41a-d. The ferrule is received in the opening forming the inlet port37a-d, and is pressed against the inlet ports37a-dby a thumb nut47a,47b,47c,47d, which screws into the projection at the inlet port37a-d. This ensures a fluid tight connection is formed where the first conduits41a-dand second conduits43a-dmeet.

The second conduit43a-dends at an outlet45which is aligned with the fluid input hole15on the flow cell1. The end of the conduit43a-dabuts the flow cell around the fluid input hole15. A recessed area105is formed in the ledge35, around the outlet45, and a seal107is received in the recessed area to form a seal between the conduit43and the flow cell1.

The first conduits41a-dand second conduits43a,43b,43c,43dform a fluid input channel for providing reagents to the flow cell1. Both the first conduits41a-dand second conduits43a-dmay be formed as flexing tubing, cavities or passages in the base portion29, as a combination of the two, or by any other suitable means.

In the example shown, the first conduits41a-dare formed by flexible tubing and the second conduits43a-dby passages in the base portion29.

A fluid outlet channel is formed by third conduits49a,49b,49c,49dand fourth conduits53a,53b,53c,53d.

The third conduits49a-dextend from inlets51a-dto outlet ports39a-d. Like the second conduits43a-d, the third conduits49a-dextend through the ledge35, the thicker portion97and the projection. The inlet51a-dis aligned with the fluid output hole17of the flow cell1. The end of the conduit49a-dabuts the flow cell1a-d. A recessed area105is formed in the ledge, around the outlet45, and a seal107is received in the recessed area to form a seal between the conduit43and the flow cell1.

Fourth conduits53a-d(seeFIG.13) are provided from the outlet ports39a-dto waste reservoirs57. At the outlet ports39a-d, the third conduits49a-dand fourth conduits53a-dare joined in a similar manner to the first conduits41a-dand second conduits43a-d. A ferrule (not shown) is formed on the end of the fourth conduits53a-d. this is received in the opening forming the outlet port39a-d, and is pressed into place by a thumb screw55a-dwhich screws into the projection.

The third conduits49a-dand fourth conduits53a-dmay be formed as flexing tubing, cavities or passages in the base portion29, as a combination of the two, or by any other suitable means. In the example shown, the fourth conduits53a-dare formed by flexible tubing and the third conduits49a-dby passages in the base portion29.

The top portion31of the body27overlies the base portion29. The top portion31is also rectangular in shape and closes the tops of the cavities33a-din the base portion29. The top portion is within the area bounded by the projections forming the inlet ports37a-dand outlet ports39a-d.

As best shown inFIGS.3and4, an underside61of the top portion may include recesses65aligned with the flow cells1a-d, such that the cavities33a-dare formed in part by the base portion29and in part by the top portion31. The height of the top portion31is such that the projections at the inlet and outlet ports37a-d,39a-dproject above an upper surface63of the top portion31.

The top portion31and bottom portion29are releasably fixed together to allow replacement of the flow cells1a-d. In the example shown, thumb screws67having enlarged heads67ato allow them to be tightened and loosened by hand are provided to secure the portions29,31together.

As shown inFIG.5, the thumb screws67are positioned at four corners of a rectangle formed by the area covered by the four flow cells1a-d(i.e. the thinner area97). The thumb screws67extend through the top portion31and bottom portion29away from the cavities33a-d.

A biasing block69a-dis provided in each cavity33a-d, between the flow cell1a-dand the top portion31. A bottom surface109of the biasing block69contacts the microscope slide3of the flow cell1a-d. The first conduit41a-dof each fluid input channel41,43runs adjacent the biasing block69.

FIG.6shows a biasing block69in more detail. In order to fit in the cavity33a-d, the biasing block is cuboid in shape, having length longer than width. A pair of first blind holes71are provided in the upper surface111, spaced along the length the biasing block69, centrally across the width.

As shown inFIGS.3, a spring73is provided between the base75of the blind holes71and the underside61of the top portion31. In the example shown, projections77extend down from the top portion31, through the centre of the spring73to locate the spring73.

The springs73apply a biasing force to urge the biasing block69away from the top portion31, and press down on the flow cell1a-d. This compresses the flow cell1a-dtogether to ensure the flow cell is enclosed with a tight seal. Furthermore, this urges the flow cell1a-dtowards the outlet45of the fluid input channel41,43and the inlet51of the fluid output channel49,53. Therefore, the flow cell1a-dforms a fluid tight seal with the inlet channel41,43and output channel49,53prevent escape of reagents.

A further blind hole79is formed in the top surface111, between the pair of first blind holes71. The further blind hole79is also positioned centrally across the width. This aligns with an opening81through the top portion31. A screw83extends through the top portion31into the further blind hole79. Tightening or loosening of the screw83varies the force with which the biasing block69pushes down on the flow cell1a-d.

A pair of elongate passages85,57extend along the length of the biasing block69from an opening in one or both ends. The elongate passages85,87are provided either side of the blind holes71,79. The heating element89is provided in the passage85closer to the conduit41for carrying reagents.

A heating element89, and temperature probe91extend through the passages85,57. Connections to the heating element89and temperature probes91pass through the top portion31of the body and through opening99in the upper surface63. A separate opening is provided for each heating element89a-dand temperature probe91a-d.

The biasing block69is made of a thermally conductive material such as aluminium, and may optionally be finished with an anodic film, such as Optical Black. Thus, when a current is passed through the heating elements89the biasing block69heats up. This in turn pre-heats the reagents as they pass through the first conduit41a-d. This may also heart the contents of the flow cell1a-d.

In use, the adapter25, with four flow cells1a-1din place in the cavities33a-dis held on a microscope stage. The adapter25is made of a standard size such that it can be held in place without modification of the microscope.

FIG.8illustrates the adapter25with an imaging apparatus93brought up to a flow cell1. The reduced thickness region97allows the imaging apparatus to be brought closer to the sample in the flow cell1a-d.

FIG.9illustrates a flow cell1according to a second embodiment. A second embodiment of an adapter25, for use with the flow cell ofFIG.9, is described with reference toFIGS.10to12. The flow cell1and adapter25shown inFIGS.9to12are the same as the flow cell1and adapter described in relation toFIGS.1to8unless explicitly stated otherwise. Like reference numerals will be used for like features.

The flow cell1of the second embodiment is identical in construction to the flow cell1of the first embodiment, except the fluid input hole15and fluid output hole17are provided in the microscope slide3rather than the coverslip5.

In use, the sample to be examined is mounted on the coverslip5, and the flow cell1assembled around this. This will be discussed in more detail below, in relation toFIGS.16to19. As in the first embodiment, the assembled flow cell1is mounted on the adapter with the coverslip5facing down. Therefore, as will be described in more detail below, the adapter is arranged to deliver the fluid from above the flow cell1rather than below the flow cell1, as in the first embodiment.

FIG.10shows a cross-sectional view of a single cavity33in the adapter25of the second embodiment, taken along the length of the cavity33.

Unlike the first embodiment, there are no conduits43,49formed in the ledge35, thicker region95or bottom portion29. In the first embodiment the ledge35and base portion extend sufficiently far under the flow cell1to reach the fluid inlet hole15and fluid outlet hole17. In the second embodiment, this is not required, and the base portion29and ledge35simply have to support the flow cell1. Therefore, the thinner region97is increased in size.

In the second embodiment, the fluid channels are formed in the biasing block69.FIG.11shows the biasing block69of the second embodiment in more detail.

As in the first embodiment, the biasing block69includes a first pair of blind holes71for receiving springs73to resiliently bias the binding block69away from the top section31and towards the flow cell1. Also, a further blind hole79is provided to receive the screw83to vary the biasing force.

In addition to the blind holes71,79, the biasing block in the second embodiment includes a pair of through passages101,103. The through passages101,103are formed at either end of the line of blind holes71,79and are formed centrally across the width of the biasing block69. To accommodate the through passages101,103, the spacing of the blind holes71,79along the length of the block is reduced in the second embodiment compared to the first embodiment.

A first through passage101of the pair of through passages aligns with the fluid inlet hole15in the microscope slide3in the flow cell, whilst the second through passage103aligns with the fluid output hole17. The lower surface109of the biasing block69includes a recessed space105′ around the ends45′,51′ of the through passages101,103. These recessed spaces150′ are arranged to receive annular sealing members107′ for forming a seal between the through passages101,103and flow cell1.

Upward extending projections113,115extend from the upper surface111of the biasing block69, around the through passages101,103, with the through passages continuing through the projections113,115.

The first projection113extends around the first through passage101and forms an inlet port37a-d. Here, the through passages101a-dconnects to the conduits41a-dthat extend from the reservoirs source59a,b. The connection may be by any suitable means, such as a ferrule and thumbscrew47a-d, as disclosed in the first embodiment, or any other suitable connector. Therefore, the first through passage101has a corresponding function to the second conduits43a-din the first embodiment, and may be considered as a conduit forming part of the fluid inlet channel.

Likewise, the second projection115extends around the second through passage103and forms an outlet port39a-d. Here, the through passage103connects to the conduits53a-dthat extends to the waste reservoir57. The connection may be by any suitable means, such as a ferrule and thumbscrew55a-das disclosed in the first embodiment, or any other suitable connector. Therefore, the first through passage103has a corresponding function to the third conduits49a-din the first embodiment, and may be considered as a conduit forming part of the fluid output channel.

As shown inFIG.12, the projections113,115in the biasing block69extend through the top portion31of the body to allow for easy connection of the first conduits41a-dand fourth conduits49a-d.

As discussed above, the biasing block69of the second embodiment is urged downwards onto the flow cell1. As in the first embodiment, this compresses the flow cell1, forming a tight seal in the flow cell. This also acts to create a tight seal between the flow cell and the fluid input and output channels.

Referring toFIG.11, it will be appreciated that the heating elements89and temperature probes91are arranged in the biasing block69in the same manner as the first embodiment. In this example, the reagents pass directly through the heated biasing block69, and are pre-heated.

In the example shown inFIG.12, a clamp149is provided. This holds down the heating elements89and temperature probes91to relieve strain. It will be appreciated that this is optional, and may be provided in any embodiment.

In the second embodiment, the removal of the fluid channels from the base portion29and underneath the flow cell1enables a greater part of the flow cell to be exposed, thus increasing the size of the viewing window of the flow cell.

A system201for immunohistochemistry analysis of samples provided in flow cells1a-dmounted in adapters25as discussed above will now be described with reference toFIGS.13to15. This system201is given by way of example only, and any suitable system may be used. It will be appreciated that the system is the same whether the flow cells1a-dand adapter25of the first or second embodiment are used.

As shown inFIG.13, reagents23a-fare provided in reservoirs59a-d. Any suitable type of reservoir may be used, such as by way of non-limiting examples, tanks, bottles, beakers, test tubes, vials, Eppendorf reservoirs and the like. The reagents23a-fmay be any suitable reagents, such as markers, quenching reagents and the like.

In one example a single reservoir may be provided for each reagent23a-f. On the other hand, multiple reservoirs may be provided.

A multi-way pump117is provided for each individual flow cell1a-din the adapter25. In the example shown a twelve way syringe pump is used, with 1 ml syringes and a minimum flow rate of between 10 μl/minute and 50 μl/minute. In some example, the flow rate may be between 20 μl/minute and 50 μl/minute

Each pump draws reagents23a-ffrom the reservoirs59a-fthrough conduits121a-d,123a-d,125a-d,127a-d,129,131. As can be seen inFIG.13separate conduits121a-d,123a-dmay be provided for each pump117afrom the reservoirs59a,59bto the pump117a. This may be the case for, for example, bulk reagents23a,23b. . . . On the other hand, other reagents23c,23dmay be drawn from the reservoir59c,59dby a single conduit125,127, which then divides into separate branches125a-d,127a-dfor each pump117.

In some cases, reagents23a-dare provided to every pump117and flow cell1a-d. In other cases, certain reagents,23e,23fmay be specific to a subset of one or more of the flow cells1a-d.

One outlet of each pump117a-dis connected to the flow cells1a-dby the corresponding first conduit41a-d. From the flow cell, reagents are carried to a waste reservoir57bthrough outlet fluid channels49,103,53.

As discussed above, in the first embodiment, the fluid input channel includes a first conduit41that extends from the pump117, through the base portion41adjacent the biasing block69and to an inlet port37a-d. The fluid input channel then continues through a conduit43formed in the base portion29and ledge35of the adapter. The outlet channel extends through a first conduit49in the base portion29and ledge35, through an outlet port39a-dand through a second conduit53.

On the other hand, in the second embodiment, the fluid input channel includes a first conduit41that simply extends to the inlet ports37a-d. The second conduit then extends through the biasing block69to the flow cell1a-d. The outlet channel extends through a first conduit103in the biasing block, to the output ports39a-dand then through a second conduit53a-dto the waste reservoir.

A second outlet of each pump117is connected directly to a bypass waste reservoir57a, without passing through the flow cell. This is connected by bypass conduits133a-d, and allows the system to be flushed, when required.

The pumps117a-dand control electronics135may be housed in an enclosure137as shown inFIG.14. The enclosure may be any suitable material, such as polycarbonate.

The pumps117a-dand/or inlet and outlet ports of the pumps may be provided to the enclosure137to allow for connection of the system201. Furthermore, as will be discussed below, a communications port139, such as a USB or ethernet port, and power socket141may also be provided on the exterior of the enclosure. In other example, the communications may be wireless by WiFi, Bluetooth or other wireless communications.

FIG.15illustrates an example of the control electronics135required for operating the system201ofFIG.13.

A separate microcontroller143a,143b,143c,143dis provided for each flow cell1a-d. The microcontrollers143a-dreceive communications over the communications port139. Any suitable communications protocol may be used, and any suitable conversion or bridge may be provided, as required.

Each controller143a-dis connected to the pump117a-dand heating element89a-dand temperature probe91a-dof the corresponding flow cell1a-d. This may be through any suitable communications, such as ethernet, relates, RS232, or any other suitable connection or driver. Furthermore, the heating elements89a-dand pumps117a-dmay also be connected to a power supply147.

The power supply147receives mains power from the power socket143, and may include a regulator and/or inverter as required.

In one example use scenario, a set temperature for each flow cell1a-d, is received over the communications socket139. The controllers143a-dthen use the heating element89a-dand temperature probe to achieve the desired temperature by selectively activating the heating element89a-dusing PID controls.

Commands may also be received over the communications socket when each pump should be activated, and which reagent should be pumped.

In this example, the operation of the system201is controlled remotely by a computer or external control device connected over the communications socket139, which sends live instructions on when to activate each pump117. The external control device may have pre-programmed routines that when started by a user, automatically run and send the required commands at the required times.

In other examples, the control electronics may include a memory that includes the desired set temperature and pump operations associated with predetermined routines. The command received over the interface may simply be a selected routine, which the controllers then perform.

On yet further examples, the operation may be distributed between the external control device and the controller143a-d. Alternatively, a user may manual input each command required in turn.

The flow cells1a-ddiscussed above are given by way of example only. The flow cell1a-dmay have any suitable arrangement and shape, with an inlet hole15and outlet hole17aligned with the fluid channels of the adapter25.

For example, the opening9in the gasket9may have any suitable size and shape. The gasket7may be any suitable material that will elastically deformed when compressed to form a sealed enclosure19.

Any suitable transparent plates of any shape and size and material can be used in place of the microscope slide3and coverslip5.

In the example discussed above, the flow cell1is asymmetric along its length, because the coverslip5and gasket7are shorter in length than the microscope slide3, and the fluid outlet hole15is spaced further from the end of the microscope slide3than the fluid inlet hole13. This is by way of example only. The microscope slide3, gasket7and coverslip5may be the same length and/or the fluid inlet hole15and fluid output hole17may be spaced equal distances form the respective ends of the microscope slide.

In one example, the apertures may be spaced by 43 mm. The opening9in the gasket7may be 36 mm by 20 mm. This may give an actual viewing area of 9 mm by 20 mm. This is by way of example only.

The adapter may be made of any suitable material. The top portion29and bottom portion31of the body may be made of metal, such as steel, plastics, ceramics, or any other material. The biasing block69may be made of any thermally conductive material.

The top portion29and bottom portion31may be releasable joined in any way. In the above examples, thumb screws67are used. However, the portions29,31may be joined by one or more of: screws, latching points, clips, snap fit projections, and the like.

The biasing block69may be biased away from the top portion69in any suitable way. In the above example, two springs are used to create two biasing points. However, there may be any number of biasing points, and any biasing means may be used. Furthermore, the biasing block may extend over one or more edge of the flow cell,1a-d, in which case, the biasing may act between the base portion29and the biasing block, to pull the biasing block towards the base portion.

In some examples, the biasing block69may be omitted. In this case, the spring73or other biasing means may act directly on the flow cell1a-d, and the heating element89may be provided in another part of the body, with the fluid input channel run adjacent to or through the heated portion to pre-heat the reagents.

Any suitable heater or heating element may be used. In one example, the heater may have a power rating of 50 W but this is by example only. In one example, the heating element is a conductive wire, but any electrical or no electric heating element may be used. In some example, the passage85may be sealed and include a fluid, heated by an immersion heater, or there may be fluid exchange to cause heating.

Any type of temperature sensor91a-dor thermocouple may be used.

The ledge35to support the flow cell1a-dmay only extend at the ends of the flow cell1a-d, only at the sides of the flow cell1a-d, or around the perimeter. The ledge35may be continuous or discontinuous around the ends and sides.

In the examples discussed above, the fluid inlet channel and fluid outlet channel are formed by two separate conduit portions. However, it may be that the channel, following the same path may be made of three or more separate portions joined together, or of a single continuous portion for each channel.

The examples shown above include four cavities33a-dflow cells1a-din the adapter. However, it will be realised that the adapter may hold any number of flow cells, having one or more cavities33. In some use scenarios, not all cavities may be filled, if the adapter includes more than one cavity33.

Any number of reagents23may be coupled to the flow cells. Each reagent may be individually coupled to each flow cell, through a corresponding pump117. Alternatively, some or all of the flow cells may be connected to the output of a single pump117.

The conduits connecting the reservoirs to the pumps117and flow cells may be any suitable tubing, piping or other mechanism for conveying fluid.

The enclosure137and control circuitry discussed above is given by way of example only, and any suitable system201may be used to operate the flow cells1a-din the adapter25.

An alignment device301for assembling a flow cell1he is shown inFIGS.16to19.

The flow cell1assembled using the alignment device301may be used with the adapters25of either embodiments discussed above.

FIGS.16A and16Bshow a first guide303of the alignment device301. The first guide303is used to apply the microscope slide3to the gasket7.

The first guide303of the alignment device301is formed by a body305that is substantially rectangular in shape. The body305includes a recess307shaped and sized to tightly receive the gasket7, and to hold the gasket7in place. The recess307has a boundary edge307awhich defines a perimeter for receiving the gasket7.

The recess307has a flat base309for supporting the gasket7. The depth of the recess307from the top surface311of the body305is such that when the gasket7is placed in the recess307, the top surface7aof the gasket7is flush with or just above the top surface311of the body305.

Projections313extend upward form the top surface311of the body305of the first guide303. The projections313define an edge to locate the slide3relative to the gasket7. In the example shown, the projections313are discontinuous around the perimeter of the slide3, and are provided at three corners, to allow the slide3to be accurately locate with respect to the gasket7.

As discussed above, the gasket7is shorter in length than the slide3. The projections313are arranged around the recess307such that the first guide303aligns one end of the gasket7at or substantially one end of the slide3, and the sides of the gasket7at or substantially at the sides of the slide3.

In the example shown inFIGS.16A and16B, the gasket7may have a curved corner7b, with a corresponding curved corner formed in the recess. This ensures the gasket7can only be placed in the recess307in a single orientation in the recess307, so the flow cell1is always assembled in the correct orientation.

As discussed above, adhesive is used to secure the slide3, coverslip5, and gasket7together. In one example, the gasket7may be have an adhesive pre-applied to both sides of the gasket7, and protected by a protective film (not shown).

In a first step of assembling the flow cell1, the protective film on the side of the gasket7facing the slide3is removed, the gasket7is placed in the recess307, and then the slide is provided within the perimeter defined by the projections313. The slide is then pressed onto the gasket7to secure the gasket7to the slide3. The combined gasket7and slide3can then be removed as a single piece, forming a component part of the flow cell1.

In the embodiment shown, a through hole315is provided through the body305of the first guide303to ease removal of the assembled gasket7and slide3, although it will be appreciated that this is optional. As best shown inFIG.16B, the through hole is aligned so that the edge of the slide3extends over the through hole315.

FIGS.17A and17Bschematically show a second guide317of the alignment device301.

Like the first guide303, the second guide317is formed by a body319that is substantially rectangular in shape. The body319includes a rectangular recess321formed in the top surface323of the body319. The recess321is defined by a perimeter edge321a, and is shaped and sized to receive the gasket7. In the example shown, the recess321does not include a curved corner, but this may be incorporated in some examples.

As in the first guide305, projections329extend upwards from the top surface323of the body319. As in the first guide305, the projections329are formed around the recess321and define an edge to locate the slide3. In the example shown, the projections329are discontinuous around the perimeter of the slide3, and are provided at three corners, to allow the slide3to be accurately locate with respect to the gasket7.

The slide3and gasket7form separate but joined portions of the component part of the flow cell1. When the component part is located in the second guide317, the slide3rests on top of the top surface323of the body319, and the gasket7sits in the recess321.

A cross bar325extends across the width of the recess321nearer one end of the recess321than the other. The cross bar325and perimeter edge321aof the recess define an area327to tightly fit and hold a coverslip5.

The recess321has a base321bon which the coverslip5can rest. The depth of the recess321is such that when the coverslip5is placed in the recess, the gasket7sits on the coverslip and the underside of the slide3sits on the top surface323of the body319. The height of the cross bar325is such that the coverslip5is flush with or slightly above the top of the cross bar325.

As discussed above, the coverslip5is shorter in length than the slide3. The recess321in the second guide317is positioned to align one end of the coverslip5with the same end of the slide3to which the gasket7is also aligned. Therefore, at one end of the flow cell1, the slide,3, coverslip5and gasket7are all aligned. The sides of the coverslip5are aligned with the sides of the slide3and gasket7.

In a second step of assembling the flow cell1, the coverslip5is placed in the area327for receiving the coverslip5. The protective film is then removed from the adhesive on the second side of the gasket7, and the combined gasket7and microscope slide3placed in the recess321, with the gasket7facing downwards towards the coverslip5. The flow cell1is then pressed together to secure the parts together.

In the embodiment shown, a through hole331is provided through the body319of the second guide317to ease removal of the assembled flow cell1, although it will be appreciated that this is optional. As best shown inFIG.17B, the through hole331is aligned so that the edge of the slide3extends over the through hole331.

When the adaptor25of the first embodiment is used, the sample to be inspected should be placed on the microscope slide3. This can be done either before the first step discussed above, or between the first and second step.

When the adapter25of the second embodiment is used, the sample to be inspected should be placed on the coverslip5. This can be done either before the first step discussed above, or between the first and second step. The sample may be placed on the coverslip5when the coverslip5is in the second guide317, or before it is placed in the second guide317.

In the steps for assembling the flow cell discussed above, the flow cell is pressed to secure the parts together. It will be appreciated that the flow cell should be pressed until wetting of the slide3or coverslip5can be seen through the adhesive, and to remove as many air pockets form the adhesive as possible.

In one example, a roller may be used to apply pressure to the assembled flow cell1.FIG.17illustrates an optional third guide333for applying pressure to the flow cell1.

InFIG.18, the third guide333is formed by a body335having a flat top surface337. A recess339is formed in the flat surface337. The recess339is shaped and sized to tightly receive the flow cell1with the coverslip5facing upwards. The depth of the recess339is such that when the flow cell1is properly assembly, the top of the flow cell1should be flush with the top surface337of the body335, or just above it.

Sidewalls341are formed along the long edges of the body335, extending upward from the top surface337and parallel to the long edges of the flow cell. The ends of the body335are open.

In use, a roller (not shown) sized to fit between the side walls341can be used to apply pressure to the flow cell. The arrangement of the third guide333ensures that the pressure is evenly applied.

An opening may be provided under the flow cell1or at an edge of the flow cell, to allow the flow cell1to be pushed out of the recess339.

Any suitable roller may be used. For example, a 40 shore soft rubber roller with 20 mm diameter may be used.

It will be appreciated that the roller is only one example for applying pressure. For example, a clamp or screw system (similar to a book press) may also be used to apply pressure. In some examples, pressure may be applied the flow cell1with the slide3facing up instead of or as well as with the coverslip5facing up.

In one example, the guides303,317,333may be arranged such that they lie parallel to any surface they are placed on. In other examples, the first and second guides303,317may be inclined to ensure the constituent parts of the flow cell1sit against the edges/projections defining their position. The guides303,317may be tilted along their long axis or across their long axis.

The separate guides303,317,333may be colour coded or have writing or other markers to help the user follow the correct procedure for assembling the flow cell1. The guides may be made of any suitable material, such as plastics, metal or the like.

In one example, the guides303,317,333of the assembly device301may be provided separately. In other examples, such as shown inFIG.19, the three guides303,317,333may be provided on a base343. The guides303,317,333may be arranged such that the long dimension of the guides303,317,333is parallel to the long dimension of the base or perpendicular, or in any other arrangement.

The assembly device301discussed above is just one example of how to assembly a flow cell1. Any suitable guidance/alignment device may be used. In some example, the flow cell1may simply be assembled by hand.

In the above example, separate guides301,317,333are used to locate the slide3relative to the gasket7and then the combined slide/gasket relative to the coverslip5. It will, however, be appreciated that the recesses may be arranged such that a single guide may be used to assemble the flow cell1. In the example discussed above, a separate guide33is provided for applying pressure, but this may not necessarily be the case. Pressure may be applied in a guide also used for assembly. Furthermore, the step of applying pressure using a roller or the like may be omitted altogether.

Furthermore, in the guides discussed above, recesses and projections are used to form locating edges to position to constituent parts of the flow cell1. This is by way of example only, and any suitable locating features may be used. The locating features may be continuous around the perimeter of the flow cell1, or discontinuous.

Any suitable adhesive may be used. In one example, the adhesive may require heat treatment, although it should be ensured that any heat will not degrade the sample under inspection.

In the example discussed above, the curved corner of the gasket to help provide the correct orientation of the gasket7. This is optional, and may be omitted, or any other orienting feature may be provided. The curved corner also enable the protective film to be easily removed from the adhesive. However, tabs, hooks or other features may be provided for this reason.

The features of the adhesive discussed above, such as the protective film for the adhesive and the curved corner are by way of example only. It will be further appreciated that these features may be applied to any embodiment of the flow cell1, and are not limited to use with the assembly device301discussed above.

In the above example, the gasket7fixed to the slide3and then the coverslip5is added. This is by way of example only, and the order of assembly of the flow cell1may be varied.