HK1025753B - Reaction vessels - Google Patents

Description

Reaction vessel

The present invention relates to vessels and devices for controlled heating of reagents used, for example, in biochemical reactions, and methods of their use.

Controlled heating of reaction vessels is often performed with solid block heaters that can be heated and cooled by a variety of different methods. Current solid block heaters are heated by electrical elements or in particular by thermoelectric devices. The other reaction vessels may be heated by halogen bulbs/air turbulators. Each vessel may be cooled by thermoelectric devices, compressor refrigeration technology, forced cooling or liquid coolant. Each reaction vessel fits into the block heater and remains hidden at a different level. The thermal contact between the block heater and the reaction vessel can thus vary according to the design of the heater. Where multiple temperature stages are required to carry out the reaction, the temperature of the block heater can be adjusted using a programmable controller so that, for example, a thermodynamic cycle can be carried out using the heater.

This type of heater configuration is particularly useful for reactions requiring thermal cycling, such as DNA amplification methods like Polymerase Chain Reaction (PCR). PCR is a method for generating large quantities of a specific DNA sequence and is based on the base-pair properties of DNA and can replicate the complementary chromosomal stretch of DNA precisely. Typical PCR involves a cyclic process of three basic steps.

Denaturation: the mixture containing the PCR reagents (including the DNA to be replicated, the individual nucleotide bases (A, T, G, C), the appropriate primers and polymerase enzyme) is heated to a predetermined temperature to separate the two chromosomes of the target DNA.

Annealing: the mixture is then cooled to another predetermined temperature and the primers place their complementary sequences on the DNA chromosome strip and ligate to it.

Extension: the mixture is again heated to another predetermined temperature. The polymerase enzyme (acting as a catalyst) attaches a single nucleotide base to the end of the primer, thereby forming a new DNA chromosome strip that is complementary to the target DNA sequence, linking the two chromosome strips together.

A disadvantage of the known block heater is that the heating block is heated and cooled to the temperature required for the reaction with a time delay. Thus, the time to complete each reaction cycle, in addition to the reaction rate, is determined to some extent by the thermodynamic characteristics of the heater. For reactions involving multiple cycles and multiple temperatures, this lag time has a significant effect on the time required to complete the reaction. Thermocyclers based on such block heaters typically take about 2 hours to complete 30 reaction cycles.

For many applications where PCR technology is used, it is desirable to complete a series of cycles in the shortest time possible. Especially if unhealthy or even life is affected, for example when respiratory air or fluids or food products consumed in large amounts by humans and animals are suspected to be contaminated, a rapid diagnostic method can save considerable money.

An alternative thermal cycler includes a set of capillary reaction tubes suspended in air. The heating and cooling of each reaction tube is accomplished with a halogen bulb and turbulent air from a fan. The thermodynamic performance of this system shows significant improvement over conventional block heater designs because the required temperature can be achieved very quickly by heating and cooling the air through the reaction tubes, and the fan provides a uniform thermal environment and intense cooling. With this apparatus, 30 reaction cycles can be completed in about 15 minutes. The disadvantages of such a thermodynamic cycle are: air cooling and heating is not well suited in multi-beam devices and is completely unsuitable in mobile or portable devices.

Applicants have developed an efficient system for rapidly heating and cooling reactants that are particularly useful in thermal cycling reactions.

Accordingly, the present invention provides an apparatus for producing a reaction, the apparatus comprising: a reaction vessel for containing reagents for controlled heating, a conductive polymer which emits heat when an electric current is passed through the polymer, and control means for controlling the electric current supplied to the polymer, the control means being arranged to supply an electric current to produce a sequence of different temperatures for the reagents contained in the reaction vessel, the polymer being connectable to a power supply means via the control means.

The present invention provides a method of conducting a chemical or biochemical reaction requiring multiple temperature stages, the method comprising: placing the reagents required to carry out said reaction in a reaction vessel comprising an electrically conductive polymer which emits heat when an electric current is passed through the reaction vessel, supplying the electric current to said polymer, thereby heating the reagents to a first desired temperature; the current is then adjusted to produce the subsequent temperature stages required for the reaction.

The present invention provides an apparatus for generating a reaction, the apparatus comprising: the apparatus comprises a plurality of reactor vessels, a conductive polymer capable of emitting heat when an electric current is passed through the vessel, and a control device for controlling the electric current supplied to the polymer, the polymer being connectable to a power supply via the control device and arranged to heat each vessel, wherein the heating of one vessel is controlled independently of the heating of a different vessel.

Conductive polymers are well known in the art and are available from Caliente System, Inc. of Newark, USA. Other examples of such polymers are disclosed in US5106540 and US 5106538. Suitable conductive polymers can generate temperatures as high as 300 ℃ and are therefore well suited for use in PCR processes, where temperatures in the range of 30 ℃ to 100 ℃ are typical.

The advantage of the present invention over conventional block heaters comes from the rapid heating of the conductive polymer. The heating rate depends on the exact properties of the polymer, the size of the polymer used and the amount used at the time. Preferably, the polymer has a high resistivity, for example, in excess of 1000 Ω. The temperature of the polymer can be easily controlled by controlling the magnitude of the current flowing through the polymer, allowing it to remain at the desired temperature for the desired amount of time. Furthermore, the rate of transfer between temperatures can also be easily controlled after correction by means of a suitable current supplied, for example under the control of a computer program.

In addition, rapid cooling can be ensured by the low thermal mass of the polymer, compared with a block heater. However, if desired, the reaction vessel may also be artificially cooled, thereby further increasing the cooling rate. Suitable cooling methods include forced air cooling, for example with an electric fan, cooling by immersion in ice or a mixture of ice and water, and the like.

In addition, the use of polymers as heating elements in the reaction vessel generally allows the apparatus to be more compact than existing block heaters, which is useful for conducting chemical reactions in field conditions such as outdoors, on rivers, on the floor of a plant or even in a small yard.

The reaction vessel may be in the form of a reagent container, such as a glass, plastic or silicon container, and is provided with a conductive polymer in close proximity thereto. In one embodiment of the vessel, the polymer is designed as a sheath that fits around the reaction vessel and is in thermal contact with the vessel. The sheath can be designed either as a shaped cover which can be designed to remain a tight fit around a reaction vessel or as a strip-shaped membrane which can be wrapped around the reaction vessel and secured.

The polymer jacket arrangement means that close thermal contact can be obtained between the jacket and the reaction vessel. This ensures that the vessel reaches the desired temperature quickly without the usual time lag due to the insulating effect of the air layer between the reaction vessel and the heater. In addition, a polymer jacket may be used to cooperate with the apparatus for using each prepared reaction vessel. In particular, a strip of flexible polymeric film may be wrapped around a variety of different sizes and shapes of reaction vessels.

Where a sheath is used, it is preferably made porous or in some form of mesh. This increases the flexibility of the polymer and makes it easier for a cooling medium to enter if the polymer itself cannot be used for cooling.

In another embodiment of the invention, the polymer is provided as a part of the whole of the reaction vessel. The reaction vessel may be made from a polymer by extrusion, injection molding or similar techniques. Alternatively, the reaction vessel can also be manufactured as a composite structure, wherein: a layer of conductive polymer is embedded between the layers of material from which the vessel is made, or the inner and outer surfaces of the reaction vessel are coated with polymer, or the vessel is made primarily of polymer coated with a thin layer of PCR compatible material. Such vessels may be made using layering and/or deposition techniques such as chemical or electrochemical deposition techniques as conventional prior art.

The individual vessels comprising the polymer as an integral part of the vessel have a particularly compact structure.

If several reaction vessels are required for a particular reaction, the electrical connections can be arranged such that a single power supply can be connected to all vessels or tubes. The reaction vessels may be arranged in an array.

Alternatively, each reaction vessel or group of reaction vessels may have its own heating profile which results from adjusting the current applied to the reaction vessel or groups. This provides a further and more important advantage for the reaction vessels with polymer according to the invention compared to solid block heaters or turbulent air heaters, wherein the individual vessels can be controlled independently of each other by their own heating profile. This means that a relatively small device can be used to perform multiple PCR assays simultaneously, although each assay requires a different operating temperature. For example, although the nucleotide sequences representing the characteristics of each organic substance are amplified at different PCR operating temperatures, various PCR tests for detecting a reasonable amount of organic substances in a sample can be simultaneously performed.

The polymer is also suitably provided in the form of a sheet material or film, for example 0.01mm to 10mm, for example 1 to 10mm, preferably 0.1 to 0.3mm thick. By using thin films, the volume of polymer required to cover a particular reaction vessel or surface can be minimized. The heating that occurs due to the flow of current through the polymer need not be distributed to a large volume of polymer material, thus reducing the time required to heat the polymer to the desired temperature.

In use, the polymer part of the reaction vessel is arranged such that an electric current can be generated in the polymer. This may be achieved by providing the polymer with respective connection points to a power source, or by inducing a current in the polymer, for example by exposing the polymer to a suitable electric or magnetic field.

The close thermal contact between the polymer and the various reagents or reagent containers, and which can be formed in the reaction vessel of the present invention, reduces or eliminates the heating effect of the air layer between the heating element and the reaction vessel.

In one embodiment of the invention, the vessel comprises a capillary tube. Since the reagent surface to volume ratio in the capillary is greater than in conventional reagent vessels, heat transfer from a capillary to the reagent in the capillary is more rapid than that obtained with conventional reagent vessels.

Alternatively, the vessel may comprise a flat support plate, for example a two-dimensional array, in particular a chip such as a silicon chip; or a slide, in particular a microscope slide, on which the reagents are supported. The plate may be made of a polymer or the polymer may be made as an integral part of the plate, or applied as a coating to one side of the plate, or as a polymer layer within a composite structure as previously described. If appropriate, particularly when the plate is a chip, the polymer may be deposited or etched on the chip in an optimized format, for example using Printed Circuit Board (PCB) technology.

This form of vessel is particularly useful for performing PCR of, for example, a tissue sample in situ.

Other suitable reaction vessels are various tubes and cuvettes well known in the art.

The present invention also provides an apparatus for reactions requiring multiple temperatures, the apparatus comprising: a reaction vessel as described above, a means for generating an electric current in a polymer and a control means for adjusting the magnitude of the current through the polymer so as to control the temperature thereof.

The control device is preferably an automatic control device such as a computer controlled interface device. By means of a programmable controller for connection to the electrical circuit on the polymer, a defined heating method, for example a defined number of cycles to form a predetermined temperature level within a predetermined time interval and dwell, can be preprogrammed with the device, including using different temperature and time profiles for different reaction vessels at the same time in the same device.

The control means may comprise a temperature monitoring device, such as a thermocouple, which monitors the temperature of the reaction vessel and supplies this information to the control system so that the desired heating and/or cooling method can be followed.

Alternatively, the temperature of the polymer can be monitored directly by measuring its resistivity, for example, the polymer heater can be designed as a resistor in a Wheatstone (Wheatstone) circuit arrangement. This avoids the use of other temperature measuring devices such as thermocouples.

Optionally, the apparatus further comprises an artificial cooling means, such as one or more fans.

The apparatus may comprise a plurality of containers. The polymer may be provided as an integral part of each container, as a sheath around each container, or may be designed such that a layer of polymer is embedded between adjacent containers. If multiple reactions are being carried out requiring the same temperature level, any electrical connection point on the polymer can be connected to a single power supply.

However, in a preferred embodiment, the device is arranged such that the polymer in contact with (or forming) a container or group of containers is connected to a separate power supply, and several containers or groups of containers are connected to different, separately controlled power supply means. With this arrangement, a plurality of different reactions requiring different temperature levels can be carried out simultaneously, when each vessel or group of vessels has its own heating element. This configuration allows the user to perform small batch reactions with a single device, which has not been possible with existing equipment. The only device available heretofore for such use has been a block heater of some design having 2 to 4 sections that can be individually heated and cooled. However, this apparatus is limited to 2 to 4 batches of reaction and has the disadvantage of slow cycle times as described above.

When the reaction vessel comprises a slide or chip, the apparatus may comprise the slide or chip, a power supply means, means for connecting a power supply to the slide or chip or inducing a current in the polymer, and means for controlling the current through the polymer layer in the slide or chip.

The reaction vessels and devices of the invention may be used in different situations where a chemical or biochemical reaction is required, for example in. The invention therefore also provides a method of performing a reaction, such as a chemical or biochemical reaction, comprising heating a respective reagent in a reaction vessel as defined above.

In addition to the amplification reactions already mentioned above, such as PCR reactions, the vessels and devices of the invention can also be used for sequencing nucleic acids and in enzyme kinetics studies, in which the activity of enzymes at different temperatures can be studied, as well as other reactions, in particular reactions involving the activity of enzymes, where it is necessary to maintain a precise temperature. The reaction vessel of the present invention may allow for precise temperatures to be achieved and maintained for a suitable period of time and then rapidly changed as desired, even in mobile or portable devices according to embodiments of the present invention.

The temperature conditions required to achieve denaturation, annealing and extension, respectively, for the PCR reaction, and the time required to perform these stages will all vary depending on different factors, as is known in the art. These factors include, for example, the nature and length of the nucleotide to be amplified, the nature of the primer used and the nature of the enzyme used. The respective optimization conditions can be determined in each case by the person skilled in the art. Typical denaturation temperatures are about 95 ℃, typical annealing temperatures are about 55 ℃, and extension temperatures of 72 ℃ are generally preferred values. When using the reaction vessel and apparatus of the invention, these temperatures are all reached quickly and the transfer rates between the temperatures can also be easily controlled.

Gene probe testers for chromosomes and chromosome strips of genetic DNA arranged one above the other, e.g. as described in US patent US5538848, registered under the trade mark Taqman^And Total Internal Reflection Fluorescence (TIRF) testers, such as those described in WO93/06241, may of course be used with various embodiments of the present invention. In such a test meter, a fluorescence monitoring device is used to detect a signal, such as a fluorescence signal or an evanescent signal, emanating from the sample. The fluorescence monitoring device must be able to detect the signal emitted from the sample while the process is being performed. In some cases this is useful because if at least part of the vessel, for example when the vessel is a tube as described in the present invention, the end will be optically transparent so that measurements can be made through it. Alternatively, the vessel is provided with means for delivering a signal from the sample to the vesselMeans for monitoring the device, such as an optical fibre or an evanescent waveguide.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows a reactor vessel heater comprising a sheath made of an electrically conductive polymer fitted around a reactor tube;

FIG. 2 shows a reaction chip having a conductive polymer coating on one surface thereof;

FIG. 3 shows a reaction slide having a layer of conductive polymer in a composite structure;

FIG. 4 shows an apparatus for carrying out a reaction involving multiple stages of temperature and heating a capillary reactor with a strip of electrically conductive polymer;

FIG. 5 shows a schematic view of an apparatus for performing a PCR reaction according to the present invention;

FIG. 6 shows a thermodynamic cycle profile for the device of FIG. 5;

FIG. 7 is a schematic diagram of a portable PCR multifunctional detector;

fig. 7a is a view of a sensing element used in the device of fig. 7.

Referring to fig. 1, a conductive polymer sheath 2 is provided with a plurality of electrical connection points for connection to a power supply. The size and shape of the jacket 2 is determined by the size and shape of the reaction vessel 1 around which it fits.

In use, the sheath 2 is placed around the reactor 1 in close thermal contact therewith. Each connection point 3 is then connected to a power supply (not shown) and current is passed through the polymer sheath 2 to heat the reactor 1 and any reagents therein.

Referring to fig. 2, a conductive polymer 2 is coated on one side of a slider 1. The electrical connection points 3 are provided at both ends of the slide board 1 and electrically connected to the polymer layer 2.

In fig. 3, the reaction vessel comprises a composite structural slide 1 with a layer of conductive polymer 2 sandwiched between layers of materials commonly used to form slides such as glass. The electrical connection points 3 are provided at both ends of the slider 1 and electrically connected to the polymer layer 2.

In use, a power supply (not shown) is connected to the electrical connections 3 on the skillets shown in figures 2 and 3 and current is passed through the polymer layer 2, thereby heating the skillet 1 and any reagents placed thereon.

Referring to fig. 4, a strip of conductive polymer film 2 is wrapped around a capillary 1 and secured. The strip-shaped polymer film 2 is provided with electrical connection points 3 to which a power supply device 5 is connected via connection clamps 4.

In use, an electrical current is passed through the polymer membrane 2, thereby heating the capillary 1 and any reagents therein.

The apparatus shown in FIG. 5 is constructed to perform PCR detection. A capillary 6 having an inner diameter of 1.12mm and an outer diameter of 1.47mm was used as a reaction vessel. A strip of conductive polymer 7 is applied to the capillary tube and secured so that the conductive polymer can be very tightly secured to the outer surface of the capillary tube. Heat can therefore be applied from all sides of the tube to minimize the temperature gradient through the sample in the capillary 6.

The heating is supplied by an electric power supply 8 connected to a computer 10 via a connection interface 9, so that the heating cycle can be automatically controlled. A fan cooler 11 is provided for directing air onto the polymer 7. An infrared thermocouple 12 is arranged outside the polymer 7 in order to track the temperature.

To evaluate the performance of the device before use, the temperature inside the tube 6 was tracked with a type K thermocouple. The outside temperature reading is then linearized with the inside and outside temperatures to a predetermined sample temperature.

The heated polymer is connected to a power supply 8 and an electrical circuit closed with a connection interface 9 and software. A switch for closing the circuit is a quick select relay that can be switched every 10 milliseconds. The second circuit is used to control two small fans 11 that rotate continuously and provide forced air cooling for the reaction samples. The control software is a lab view (LabView) software that provides a user with a friendly graphical interface that can be used for both programming and operation. The current is initially applied at a relatively high frequency in order to more rapidly reach the desired temperature. When the specified operating temperature is reached, the current is applied at a lower frequency to maintain the specified operating temperature for a predetermined duration.

The apparatus shown in FIG. 7 includes a covered and insulated junction box defining a plurality of test element receiver mounts 71. The cassette 71 is shown connected to a power source 73 and a computer 74 via an interface unit 72. This connection is made so as to allow a different supply of power to each support 71. Each holder contains a thermocouple (not shown) for tracking the temperature therein.

The sensing element shown in figure 7a comprises a reaction tube 75 surrounded by a sheath 76. The sheath 76 is made of a heating polymer and is connected to power supply terminals 77 and 78.

After the tube 75 has been filled and stopped, it can be supplied to the appropriate holder 71 until the respective terminals 77 and 78 have been clamped onto the mating receiver terminals in the respective holder (not shown). The arrangement of the device when fully connected may allow the connection status of each tube 75 to be displayed on a computer screen.

Closing the lid of the junction box 70 allows for the insulation of each seat and for the retention of each tube 75 in its seat.

The computer program is designed to identify the molecule to be retrieved in each tube 75 individually in order to control the appropriate temperature cycling for the PCR to amplify the molecule, if present. When the cycle is complete, the contents of the tube are exposed to a suitable gene probe detector to determine if the retrieved molecule is indeed present.

Of course, the principle of the device described in fig. 7 and 7a can also be implemented in different ways. The device may be mobile rather than portable and is designed to receive a sensing element other than a tube in a form including a slide. Typically the device is designed to handle 96 or 192 detection elements.

The following examples may illustrate the invention.

Examples of the invention

Amplification of DNA

Using the apparatus described in FIG. 5, the following PCR reaction was performed with the type K thermocouple removed.

A100-basepair amplified clone (amplicon) was amplified from a clonally processed Yersinia black death fragment. The reaction conditions have been previously used with RapidCycler of Edhol (Idho)^TMThe instrument was optimized for the same reaction mixture sample as the RapidCycler controlling the reaction in Edward, Holo (Idho)^TMAmplification was performed in the instrument.

The reaction mixture placed in tube 6 comprises the following components:

50mM 3.HCL PH 8.3，

3mM MgCl₂

2.5mg/ml bovine plasma protein

200. mu.M each of dATP, dTTP, dCTP and dGTP

The primers for each PCR were 10. mu.g/ml,

25 units/ml Taq polymerase

The thermal cycling profile as shown in fig. 6 was programmed to 95 c 0 sec, 55 c 0 sec, 72 c 0 sec. By way of comparison, a similar thermal cycling profile was programmed into the Idaho RapidCycler^TMIn the instrument. In a polymer-coated capillary vessel 6 and Idaho RapidCycler^TMA reaction volume of 50. mu.l was used in both instruments.

Herein, "0 second" means: once the target temperature is reached, the program instructs the introduction of the next temperature. The precise time that the reaction is held at the target temperature is therefore dependent on the parameters and performance of the apparatus in use. But this time is typically less than 1 second.

After 40 cycles in the capillary vessel, 50. mu.l of PCR product from each reaction was divided into size fractions in a 2% gel contained in a 1XTAE buffer by means of agar-agar gel electrophoresis. The DNA was visualized by staining with ethidium bromide. The sample was incubated with a reagent derived from Idaho Rapidcycler^TM(25 cycles) a sample obtained in the instrument was placed adjacent to each other and a similarly suitably sized amplified clone (amplicon) was detected.

Claims (35)

1. An apparatus for generating a reaction, the apparatus comprising: a reaction vessel for containing reagents for controlled heating, a conductive polymer which emits heat when an electric current is passed through the polymer, and control means for controlling the electric current supplied to the polymer, the control means being arranged to supply an electric current to produce a sequence of different temperatures for the reagents contained in the reaction vessel, the polymer being connectable to a power supply means via the control means.

2. The apparatus of claim 1, wherein: comprises a plurality of reaction vessels.

3. The apparatus of claim 2, wherein: different currents may be supplied to heat each or each group of vessels.

4. The apparatus of claim 3, wherein: the control device is provided for supplying each reaction vessel with an electric current for generating a different temperature and/or time profile.

5. The apparatus of any of claims 1-4, wherein: each reaction vessel includes a container for reactants, and the heater polymer is adjacent to the container.

6. The apparatus of claim 5, wherein: the heater polymer forms a sheath around the container.

7. The apparatus of claim 5 or 6, wherein: the heater polymer is in the form of a film.

8. The apparatus of claim 6 or 7, wherein: the sheath is integral with the container.

9. The apparatus of any of claims 5-8, wherein: the heater polymer is porous or mesh-shaped.

10. The apparatus of any of claims 1-4, wherein: the heater polymer forms a reservoir for each reactant.

11. The apparatus of any of claims 1-10, wherein: the reaction vessel comprises a container for each reactant, wherein one of the surfaces of the container is coated with said heater polymer.

12. The apparatus of any of the preceding claims, wherein: each reaction vessel includes a capillary tube.

13. The apparatus of any of claims 1-11, wherein: the reaction vessel includes a slide plate.

14. The apparatus of any of claims 1-11, wherein: the reaction vessel includes a chip.

15. The apparatus of any of the preceding claims 2-14, wherein: comprising a plurality of reaction vessels arranged in an array.

16. The apparatus of any of the preceding claims, wherein: the control device is provided for supplying an electric current such that a plurality of temperature stages required for the respective reaction occur in the respective reaction vessel.

17. The apparatus of claim 16, wherein: the control means is programmed so that multiple cycles of the reaction can be carried out automatically.

18. The apparatus of claim 16 or 17, wherein: the control means are arranged to supply current according to a predetermined time/temperature profile.

19. The apparatus of any preceding claim, wherein: also included is a device for detecting a signal emitted from a sample in a reaction vessel.

20. A method of performing a chemical or biochemical reaction requiring multiple temperature stages, the method comprising: placing the reagents required to carry out said reaction in a reaction vessel comprising an electrically conductive polymer which emits heat when an electric current is passed through the reaction vessel, supplying the electric current to said polymer, thereby heating the reagents to a first desired temperature; the current is then adjusted to produce the subsequent temperature stages required for the reaction.

21. The method of claim 20, wherein: this reaction is a DNA amplification method.

22. The method of claim 21, wherein: the amplification method is a Polymerase Chain Reaction (PCR).

23. The method of any of claims 20-22, wherein: reagents for a plurality of reactions are each placed in a reaction vessel and heated simultaneously.

24. The method of claim 23, wherein: each reaction vessel is individually heated to the temperature required for carrying out the reaction in that vessel.

25. A reaction vessel comprising a slide or a chip and an electrically conductive polymer which emits heat when an electric current is passed through said polymer, said polymer being arranged to heat a reactant on said slide or chip.

26. A reaction vessel according to claim 25, wherein: the polymer is integral with the sled or chip.

27. An apparatus for generating a reaction, the apparatus comprising: the apparatus comprises a plurality of reactor vessels, a conductive polymer capable of emitting heat when an electric current is passed through the vessel, and a control device for controlling the electric current supplied to the polymer, the polymer being connectable to a power supply via the control device and arranged to heat each vessel, wherein the heating of one vessel is controlled independently of the heating of a different vessel.

28. The apparatus of claim 27, wherein: each reaction vessel includes a container for reactants, and the heater polymer is adjacent to the container.

29. The apparatus of claim 28, wherein: the heater polymer forms a sheath around the container.

30. The apparatus of claim 28 or 29, wherein: the heater polymer is in the form of a film.

31. The apparatus of claim 29, wherein: the sheath is integral with the container.

32. The apparatus of any of claims 27-31, wherein: the heater polymer is porous or mesh-shaped.

33. The apparatus of claim 27 or 28, wherein: the heater polymer forms a reservoir for each reactant.

34. The apparatus of any of claims 27-32, wherein: the reaction vessel comprises a container for each reactant, wherein one of the surfaces of the container is coated with said heater polymer.

35. A reaction vessel comprising a container and a conductive polymer suitable for use in the apparatus of any one of claims 1 to 19 or 27 to 34.