FIELD OF THE INVENTIONThe present invention relates to a reaction vessel for use in parallel synthetic chemistry and other chemical applications where a multiplicity of chemical reactions is performed in small reaction medium volumes.[0001]
The invention further relates to a method for manufacturing such a reaction vessel.[0002]
The invention further relates to a reaction block comprising such a reaction vessel.[0003]
The invention further relates to a parallel reaction assembly comprising such a reactor block.[0004]
BACKGROUND OF THE INVENTIONCombinatorial chemical synthesis requires simultaneously performing a plurality of chemical reactions. Often the problem of separating and characterizing the reaction products has to be solved. Reactor vessel arrays have been developed, wherein one specific reaction or sequence of reactions is performed on one or possibly a small number of reactants in each vessel, so that one or a small number of products are obtained, which may more easily be separated or examined. This type of synthesis is named “parallel synthetic chemistry” due to the relatively large number of reactions performed in parallel.[0005]
In order to obtain a high performance, synthesizers enabling performing chemical synthesis in solution, on solid phase supports or in so-called “tea-bags” etc. are required. A known type of synthesizer is characterized by the following features:[0006]
a dispensing system using one or more dispensing needles (these liquid handling systems were originally used for biological screening or diagnostic techniques);[0007]
a reactor block comprising a number of reactor vessels which allow performing a plurality of chemical reactions at varying temperatures, with shaking and under inert gas; and[0008]
a computer running a specialized software package which allows the programming and control of the individual synthesis steps.[0009]
Most known reactor blocks comprise a plurality of small reactor vessels which each have a top opening closed by a piercable closure, contain an inert gas atmosphere and are accessible through the closure using a needle. Liquids are added and removed through one and the same access. Less often reactor vessels are used which allow liquid transfer through the bottom of the reactor vessel using additional valves. Hence, the known reactor vessels are characterized either by a rather complicated access or a complex structure making them expensive.[0010]
SUMMARY OF THE INVENTIONAn object of the present invention is to provide a reaction vessel which is more efficiently manufactured and is thus less expensive.[0011]
A further object of the invention is to provide a reaction vessel which allows a more convenient exchange of the vessel's contents.[0012]
Another object of the invention is to provide a reaction block, which can be used more conveniently than existing systems, particularly within an automated system, and is adapted for receiving a reactor vessel array.[0013]
According to one aspect of the invention a reaction vessel that satisfies at least one of the stated objects comprises[0014]
a body made of a material, particularly a thermoplastic polymeric material, formable an injection molding process, said body comprising[0015]
a reaction chamber defining a longitudinal axis, having a space therein for receiving a reaction medium and a discharge channel, said reaction chamber and said discharge channel each having an open end and a bottom portion, and[0016]
a fluidic connection channel that connects the discharge channel with the space within the reaction chamber,[0017]
the reaction chamber and the discharge channel each extending from its open end towards its bottom portion with constant or decreasing cross section, so that the reaction chamber and the discharge channel may be formed in an injection mold by cores which can be retracted through the respective open ends.[0018]
A reaction vessel according to the invention is formed from a polymeric material and is preferably formed by injection molding. The vessel provides a reaction space with an exit connected to a discharge channel. By application of reduced pressure to the discharge channel to a level below ambient pressure, the content of the reaction space, particularly a liquid, is discharged through the discharge channel.[0019]
Preferably, the exit of the reaction space to the discharge channel is closed by a filtration materialso that the withdrawn content is filtered as it is withdrawn. In this configuration, it is possible to use e. g. loose beads of a solid substrate, e.g. a resin, whereon the reactive component is immobilized.[0020]
Another aspect of the invention is a method for manufacturing a reaction vessel that comprises[0021]
forming said body of said vessel in an injection molding device by injection molding a thermoplastic polymeric material in a mold,[0022]
the interior of said discharge channel being shaped by a first core and the interior space of the reaction chamber being shaped by a second core, moving said first and second core being into the mold before injection of molten thermoplastic material and retracting said cores during opening of the mold after allowing a sufficient time for the molten material to harden, said second core which shapes the reaction chamber space bearing a movable extension at the end thereof which forms the bottom of the reaction chamber, and said extension touching the first core which shapes the discharge channel when said first and second core are moved into the mold, thereby forming said connection channel between said reaction chamber space and said discharge channel.[0023]
Yet another aspect of the invention is a reactor block for performing a multiplicity of chemical reactions simultaneously, particularly for use in parallel synthetic chemistry, that comprises[0024]
at least two rows of at least two locations for receiving reaction vessels, the reaction vessels having each at least an inlet and an outlet orifice and being preferably reaction vessels according to the present invention as described herein,[0025]
wherein the reactor block comprises first closure means having openings therethrough and surface parts including pins each being movable in a sliding manner over the inlets and outlets of a number, preferably a row, of reaction vessels situated in the locations into between at least one opening position, where the openings in the allow access to the inlets and/or outlets, and a closed position wherein the inlets and outlets are closed by said surface parts of the first closure means resting on the inlets and outlets.[0026]
A further aspect of the invention is a parallel reaction assembly that comprises a reactor block and reaction vessels according to the invention.[0027]
The reaction block according to the invention has been specifically designed to facilitate automation and ease of use. In this context, the closing mechanism has been realized by a movable closure means that is guided by guiding means of the block. The closure means extends over a subset of the vessels contained in the block, e. g. preferably one row, and comprises means for enabling access to the openings of the reaction vessels and for closing them, e.g. openings in the closure means alignable with the openings of the reaction vessel and sealing surfaces for closing the reaction vessels.[0028]
Furthermore, the guiding means comprise redirecting means, like gates (grooves) or a lever mechanism interacting with corresponding means provided at the closure means. The redirecting means convert a substantially linear movement of the closure means at least near the closing end position in a movement towards the openings of the reaction vessels in order to close them. Preferably, the closure means is further urged against the openings to substantially seal the opening even if a pressure greater than ambient develops in the vessels.[0029]
BRIEF DESCRIPTION OF THE DRAWINGSThe subject invention will now be described in terms of its preferred embodiments with reference to the accompanying drawings. These embodiments are set forth to aid the understanding of the invention, but are not to be construed as limiting.[0030]
FIG. 1[0031]ashows a cross-sectional view of a reactor vessel along line I-I in FIG. 1b;
FIG. 1[0032]bshows a top view of a reactor vessel;
FIG. 1[0033]cshows an enlarged partial cut along line I-I in FIG. 1b, also showing a withdrawal needle tip;
FIG. 2 shows a view perspective exploded view of a reactor block;[0034]
FIG. 3 shows a top view of the reactor block in FIG. 2;[0035]
FIG. 4 shows a cross-sectional view along line A-A in FIG. 3;[0036]
FIG. 5 shows a cross-sectional view along line B-B in FIG. 3;[0037]
FIG. 6 shows a cross-sectional view along line C-C in FIG. 3;[0038]
FIG. 7 shows a side view of the reactor block, showing the locking mechanism in opened position, according to arrow D in FIG. 3; and[0039]
FIG. 8 shows a side view of the reactor block, showing the locking mechanism in closed position, according to arrow E in FIG. 3.[0040]
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTSReaction Vessel[0041]
FIG. 1[0042]ashows a longitudinal section through areaction vessel1, FIG. 1ba top view on it. The body ofvessel1 is preferably formed from a thermoplastic material, e.g. a polymeric material which is shapable by injection molding and which is substantially inert under the conditions of the intended reactions. Preferred vessel body materials are polypropylene or a fluorinated polymer like e.g. a poly-co-ethylene-tetrafluoroethylene, particularly the one marketed under the tradename TEFZEL (DuPont).
The body of[0043]vessel1 comprises areaction chamber space3 and adischarge channel5.Discharge channel5 has anexit opening16 and a bottom portion.Reaction chamber3 has anupper opening17 and a bottom portion.Upper opening17 ofreaction chamber3 and exit opening16 ofdischarge channel5 are located at theupper rim18 ofreaction vessel1.
As shown by FIG. 1[0044]a, dischargechannel5 is arranged preferably parallel or substantially parallel to a longitudinal axis X ofreaction chamber space3, and aconnection channel part14 fluidly connectsdischarge channel5 with withinreaction chamber space3 where a reaction medium is received. Reaction medium contained inreaction chamber space3 can thus be withdrawn throughchannel part14 intodischarge channel5.Channel part14 has afirst orifice7 located near to or at the bottom ofreaction chamber space3, a second orifice located at the lower end ofdischarge channel5, and a bent, tapered shape with the narrow end at thelower end12 ofdischarge channel5.
In a preferred embodiment shown by FIG. 1[0045]a, dischargechannel5 substantially extends within and along a lateral wall9 ofreaction chamber space3. In another embodiment (not represented in the drawings)discharge channel5 substantially extends on the outer surface of and along a lateral wall ofreaction chamber space3.
A[0046]seat8 is provided in the wall9 ofreaction vessel1 at the level oforifice7 ofconnection channel part14. Afiltration material10 is placed inseat8.Filtration material10 constitutes the bottom wall of thereaction chamber3 and serves as a filter during discharging of thereaction chamber3.Filtration material10 thus constitutes a delimitation ofreaction chamber3 and preferably a delimitation of the bottom ofreaction chamber space3.Filtration material10 may be a chemically inert fiberous filtration material, a porous fused metallic, polymeric, glass or ceramic matrix. Preferably,filtration material10 is formed from a porous fused ceramic or glass matrix, i.e., a fritted filter.
[0047]Reaction vessel1 has acollar15 near itsupper rim18.Collar15 serves as an abutment whenvessel1 is inserted in a reaction block as described hereinafter.
[0048]Inlet opening17 ofreaction chamber space3 and exit opening16 ofdischarge channel5 are interconnected by a channel orgroove19, which substantially equalizes any pressure difference betweenreaction chamber space3 and dischargechannel5 ofreaction vessel1.
When a suction device, preferably a[0049]needle201, is introduced through exit opening16 ofdischarge channel5 and positioned as shown by FIG. 1cfor withdrawing the liquid contents ofreaction vessel1 throughdischarge channel5, the tip ofneedle201 is in sealing contact with a taperingportion20 of thedischarge channel5. Thereby,channel19 is fluidically disconnected fromdischarge channel5, and by applying a sufficient pressure less than ambient pressure inspace3, to discharge channel throughneedle201, the reaction vessel contents can be withdrawn.
[0050]Reaction vessel1 may be conveniently manufactured by injection molding.Reaction chamber space3 andconnection channel14 are preferably shaped by a core with a hingedly attached extension for theconnection14. The vertical part ofdischarge channel5 is preferably shaped by a second core. In the closed state of the injection molding tool, the cores are inserted within the mold cavity, the hingedly attached extension abutting on the end of the second core whereby the mold part for the hollow interior of the discharge conduit is constituted.
After injection of the molten polymeric material and allowance of sufficient time for the molten material to solidify, the cores are withdrawn. For this purpose, the extension of the first core makes a rotational movement on its hinge. The removal is facilitated by the preferred significantly tapered shape of the[0051]connection channel14. For even better removal of the cores, the walls ofreaction chamber space3 and/or thedischarge channel5 are preferably slightly tapered so that their cross sections decrease from theirupper opening17 respectively exit opening16 towards their respective bottom portions. The taper of the walls of the reaction chamber space can be so small that its cross-section can be considered to be substantially constant along the length of the reaction chamber space. This configuration ofreaction chamber space3 and discharge channel makes possible to retract the above mentioned first and second molding cores throughupper opening17 and exit opening16 respectively.
As molds of the above-mentioned kind, even including the mentioned cores, are known to persons skilled in the art, a detailed description of such molds with reference to figures is deemed unnecessary and, therefore, not included in the present specification.[0052]
From what is explained above, it is evident that[0053]reaction vessel1 is suitable for being efficiently manufactured in large numbers at a low price.
With regard to a preferred use of[0054]reaction vessel1, another advantage consists in that when a reaction is terminated, the liquid contents ofreaction chamber3 can be withdrawn throughfiltration material10 and dischargechannel5 by applying the suction device to exitopening16. In the solid-liquid reaction arrangement most often used in combinatorial chemistry, the reaction partners are immobilized on a solid support material that is retained in thereaction chamber space3 as a “filter cake” onfiltration material10.
In case that[0055]filtration material10 is occluded, it is usually possible to inject an inert gas, e. g. argon, in the reverse direction (opposite to flow direction when contents of reaction chamber is withdrawn throughfiltration material10,connection channel14 and discharge channel5) throughfiltration material10 for restoring the permeability offiltration material10. The above mentioned injection of inert gas may also be used for agitating the contents of the reaction chamber and providing a substantially inert atmosphere for conducting the reaction.
Experiments have shown that the above described structure of[0056]reaction vessel1 may withstand a moderate pressure gradient above ambient.Reaction vessel1 thus allows a reaction to be conducted even under moderate overpressure without a venting provision, e. g. to work at an elevated temperature with respect to the temperature during filling.
In a preferred use of[0057]reaction vessel1, the above-mentioned moderate pressure above ambient is generated by closing the vessel and increasing the temperature.
Typical dimensions of the
[0058]reaction vessel1 are:
| |
| |
| Cross-sectional area of the | | 10 to 1000 mm2 |
| reaction chamber: |
| | preferably | 75 to 120 mm2 |
| Length of reaction chamber: | | at least 10 mm |
| | preferably | 20 to 200 mm |
| Cross-sectional area of the | | at least 0.8 mm2 |
| discharge channel: |
| | preferably | 0.8 to 25 mm2 |
| |
Generally, the cross-sectional area of[0059]discharge channel5 is significantly smaller than the cross-sectional area ofreaction chamber space3.
As can be recognized from the above-description,[0060]reaction vessel1 shown by FIGS. 1a-1cmay be conveniently manufactured by injection molding as an integrally manufactured single-piece element, with exception offiltration material10 being inserted therein aftervessel1 is formed.
Method For Manufacturing The Reaction Vessel[0061]
A method for manufacturing the above-described[0062]reaction vessel1 comprises forming the body ofvessel1 by an injection molding process of a theromoplastic polymeric material in a molding tool, whereby
the interior of[0063]discharge channel5 being formed by a first core and the interior ofreaction chamber space3 being formed by a second core,
the first and second cores being moved into the mold before injectiing of molten polymeric material and being retracted after allowing sufficient time for the molten polymer material to harden, during opening of the mold,[0064]
said second core which shapes the reaction chamber space having a movable extension at the end thereof for forming the bottom of the reaction chamber, and[0065]
said extension touching the first core thereby forming the discharge channel when said first and second core are disposed the mold in order to form the connection channel between the reaction chamber and the discharge channel.[0066]
Reactor Block[0067]
FIG. 2 shows an exploded view of a[0068]reactor block21 containing24reaction vessels1.Reactor block21 consists of a base22 with an integrated conduit (connectors23 and24) for temperature control.Base22 comprises receivingsites26 each adapted for receiving areaction vessel1. Heat is exchanged by air between thereaction vessels1 and the walls of receivingsites26. For an efficient thermal contact, thesites26 are shaped closely similar to the exterior surface of thevessels1. As shown by FIG. 4, heat exchange (normally heating) is however substantially restricted to the lower part of thereaction vessels1 in order that vaporized liquid may condense in the cooler upper part of the reaction vessels and flow back into the reaction volume proper located above filtration material10 (reflux condensation).
A[0069]vessel holder29 is arranged above thebase22 and held by an appropriate, adjustable means (not shown) so that the vessels extend into thebase22 without touching the bottom of their receivingsites26 in order to compensate for thermal expansion and manufacturing tolerances.
[0070]Vessel holder29 comprises an array of at least two rows of at least twolocations31 for reaction vessels. Each oflocations31 has a circumferential shoulder ordepression33 for receiving thecollar15 of areaction vessel1. Theupper rims18 ofreaction vessels1 preferably project slightly above theupper surface35 ofvessel holder29. Being arranged outside of the reaction chamber's wall, due to the relative position of thedischarge channel5 with respect to thereaction chamber3 of each vessel, dischargechannel5 also serves as positioning means which allow insertion of thereaction vessels1 in only one orientation so that theupper openings17 of thereaction chambers3 and theexit openings16 of thedischarge channels5 are always in the same predetermined position. This is important for the use ofreactor block21 with automated handlers, e. g. synthesizers or analyzers.
A sealing foil or[0071]plate36 and aslider gate plate37 are placed on top of thevessels1, theslider gate plate37 being firmly pressed against theholder29 so that preferably a gas-tight sealing, or at least a fluid-tight sealing between theseal36, therim18 of thevessels1 and theslider gate plate37 is obtained.Slider gate plate37 has guidingslots48.
The[0072]seal36 and theslider gate plate37 each provide corresponding holes for each vessel, namely afirst hole39 respectively, a second42 hole corresponding toupper opening17 ofreaction chamber3 and athird hole40 respectively, afourth hole43 corresponding to the exit opening16 ofdischarge channel5. The upper ends ofholes42,43 in theslider gate plate37 are surrounded by acollar45 whose upper rim serves as a sealing surface as will be explained below. Another advantageous effect ofcollar45 is that it prevents that any spoiled matter inslot48 from flowing into the open reaction vessels.
The[0073]reaction vessels1 are preferably arranged in six rows of 4 vessels each (corresponding to a standard 24-well plate).Slider gate plate37 has aslider guiding slot48 for each row ofvessels1. Thewalls50 of theslots48 containgates52, i.e. guiding grooves or channels for closure sliders55 (four of sixnecessary sliders55 are shown).
[0074]Closure sliders55 preferably have a shape that allows them to slide freely within the guidingslots48. Their lateral faces comprisepins57 which are adapted to be slidably registered in thegates52. For assembly purposes,gates52 are open at oneend58 so that thepins57 of thesliders55 may be inserted intogates52 from above.
FIG. 4 shows a sectional view wherein some aspects mentioned above more clearly illustrated with the[0075]reaction vessels1 are merely schematically shown.Conduits60 for the temperature control medium are arranged inbase22.Vessels1 are preferably held by theholder29 in a suspended manner, extending into receivingsites26 of base22 preferably without touching the bottom62 thereof.Seal36 is pinched betweenslider gate plate37 and theupper rim18 of thereaction vessels1 whereby thecollars15 of thevessels1 are pressed down in thedepressions33.
The[0076]exit openings16 ofdischarge channels5 and the open upper ends17 ofreaction chamber spaces3 are accessible throughholes40 respectively39 inseal36 and holes43 respectively42 inslider plate37. Depending on the position of thesliders55, holes42,43 are accessible from the exterior throughholes64 respectively65 (seeslider66 on the left), or closed altogether by the slider (seeslider67 on the right) as explained more in detail below.
FIG. 3 shows a top view of[0077]reactor block21 and in particular ofslider gate plate37. For the sake of simplicity, fourslider slots48 in the middle are shown without sliders.Slider66 on the left side is in open position allowing access to the reactor vessels located below by registering itsholes64,65 with theholes42,43 inslider gate plate37.Slider67 on the right side is in closed position, i.e. a position at which the reaction vessels located below are substantially hermetically sealed, e. g. for performing the reactions.
As shown in FIGS. 5 and 6,[0078]slider66 is not only moved along guidingslot48, but abides in a slightly elevated position due to thepins57 resting on thefront surface part70 of thegates52. At the same time, in abutting against thefront wall72, the movement of theslider66 is stopped in the opened position. Theholes64,65 are aligned, and e. g. by means of a syringe, a medium can be injected into the reaction vessel throughholes64,42,39 and theopen end17 of thereaction chamber space3, or withdrawn (not shown) through theholes65,43,40 and the exit opening16 of the discharge channel5 (see FIG. 4).
In a preferred embodiment, reaction to be removed from[0079]reaction chamber space3 ofvessel1 is removed by applying a pressure below ambient or vacuum to the exit opening16 of discharge channel5.For this purpose, dischargechannel5 has an upper portion which ends atexit opening16 and which has a cross-section which is slightly larger than the cross-section of the lower portion of discharge channel and preferably vacuum is applied by means of a needle of a syringe which has a diameter equal or slightly bigger than the diameter of an lower portion ofdischarge channel5. When the front end of the syringe needle is inserted into the upper part ofdischarge channel5, a substantially tight seal is established between the needle tip and the wall of thedischarge channel5. For this purpose, the upper portion ofdischarge channel5 has preferably a conical part which narrows into the lower portion ofdischarge channel5.
In another preferred embodiment, the transition between the lower and the upper part of[0080]discharge channel5 is a single step. In this case a needle or a tube having a transversely cut end is used and this cut end forms a seal when pressed against the step.
Holes[0081]43 and65 (and42 and64) preferably have diameters larger than the conducting means (tube, syringe needle) used to inject or withdraw reaction medium in order to permit a free passage of the conducting means.
FIG. 7 shows the open configuration. FIG. 8 shows the closed configuration. As can be appreciated from these figures, during movement of[0082]slider67 to the rear position thepins57 are forced to move downward along therear part76 ofgates52, and therefore theslider67 as well. Thereby, the end phase of the longitudinal rearward movement ofsliders55 in guidingslots48 is transformed in a movement towards thereaction vessels1, and, resulting in a force pressing thelower surface79 of sliders55 (exemplarily, slider67) against thecollars45.
An advantage of the arrangement of the sliders[0083]56 of the invention just described is that a simple, e. g. pneumatic or solenoid, actuator providing a sufficient powerful, yet only linear movement, may be used for moving the sliders between the open and the closed position. This arrangement even facilitates moving of these sliders by hand.
As this closing movement of the[0084]sliders55 requires still a minimal lateral movement overcollar45,sliders55 preferably have a smooth,plane sealing surface79 in the respective parts of their lower surface.Sliders55 are preferably entirely made of a suitable polymeric material, e. g. a fluorocarbon type. Assliders55 may as well be produced by injection molding, preferably with a smooth finishtreatment of their sealingsurface79, they may be produced at a sufficiently low price to allow their use as a single-use disposable components.
Due to the fact that[0085]sliders55 are pressed with a rather elevated force againstopenings42,43, the technique used for performing reactions can be simplified: According to the prior art, vaporized solvent has been refluxed in the upper, cooler part of the reaction vessels. Solvent not condensed could escape by a venting provision, normally connected to an inert gas source. In contrast with the prior art, when a reactor block according to the invention is used, the reaction vessel may be kept closed, i.e. the reaction is carried out under moderate pressure above ambient pressure. By experiment, it has been found that preferred reaction assembly including thereaction vessel1 of the invention can withstand the pressures developed within the reaction vessel under normal reaction conditions substantially without problems.
An inert gas blanket may be provided if necessary during exchange of the reaction medium.[0086]
Within the scope of the invention a reactor block having the above-described features is used to build a parallel reaction assembly comprising[0087]reactions vessels1 having the above described features. A preferred use of such a parallel reaction assembly is for simultaneously performing a chemical reaction in each reaction vessel in the reactor block.
From the exemplary embodiment set forth above, the one skilled in the art is able to derive numerous variants without leaving the scope of protection which is intended to be solely defined by the appended claims. Some variations that fall within the scope of the invention are e.g.:[0088]
The[0089]reaction vessels1 may consist of other materials, like metal, ceramics, or even glass. Due to their rather simple structure, even with these materials, mass production methods are suitable for producing the vessels.
The sealing plate or foil[0090]36 may be left out if the contact between the reaction vessel and the lower surface of thegate plate37 provides a sufficiently tight seal.
The[0091]sliders55 may be connected to the gate plate by another mechanism, for example using levers, for transforming the movement of the sliders into one urging thesliders55 against theopenings39,40, though the preferred arrangement using pins and gates has proven to be the most reliable due to its simplicity.
The number of vessels contained in a reactor block may be varied as needed. Particularly preferred are arrangements adapted to the configuration of well plates (e. g. 96 wells, 384 wells) so that by means of a robot, whole rows of the well plate contents may be transferred to the reactor's vessels with only simple movements.[0092]
The[0093]connection channel14 may have its sampler orifice close to the discharge channel if the molding core used to formconnection channel14 is to be retracted through the discharge channel. The connection channel may also have a constant cross-section over its length or may have its narrowest cross-section between its two end orifices and the mold used to form the connection channel may in principle be retractable through either the reaction chamber or the discharge channel or both the reaction chamber and the discharge channel.
The[0094]collar45 may be omitted. Preferably, then, the sealing surfaces are slightly elevated with respect to the surrounding lower surface of thesliders55 in order to concentrate the closing pressure to theholes43,42.
The preferred arrangement of one pair of[0095]pins57 per vessel which helps to secure a substantially tight seal may be varied in using more or less pins and gates. Particularly if less pins are provided, and the sliders are somewhat flexibile, additional measures have to be applied for securing a substantially tight seal. These additional measures may be a rigid back, for instance formed from metal or some other substantially rigid material.
For particular applications the hollow interior parts of the[0096]reaction vessel1 may have other cross sections than circular, e.g. tetragonal, hexagonal or elliptic while still being within the scope of the present invention.
Although[0097]depression33 for receiving thecollars15 of the reaction vessels is preferred,collars15 may also be applied flat to the surface of thevessel holder plate29 comprising thelocations31.
[0098]Reaction vessel1 of the inventionis usable in other applications, where exchange of a reaction chamber's contents by vacuum assisted withdrawal is needed. This includes individually performing reactions in a single reaction vessel.
Instead of a pressure equalizing channel or[0099]groove19, other means for equalizing the pressure may be provided and are considered within the scope of the invention, e.g. a hole that communicates the reaction chamber and the discharge channel. Pressure equalizing means like channel or groove19 may also be entirely omitted for particular applications.