WO1997014041A9

WO1997014041A9 - Reaction block wash station

Info

Publication number: WO1997014041A9
Application number: PCT/US1996/016099
Authority: WO
Filing date: 1996-10-07
Publication date: 1997-10-16

Abstract

A reaction block wash station (400) is described. An array of pipetting needles (408A, 408B) can introduce an appropriate reagent or solvent into all reaction chambers of a reaction block (140A, 140B) simultaneously. The wash station (400) may also include a vortexing docking station (300) which provides for secure registration of the reaction blocks (140A, 140B), and provides for introduction of gases and liquids into the reaction blocks (140A, 140B). The reaction block wash station (400) may be computer controlled.

Description

REACTION BLOCK WASH STATION

FIELD OF THE INVENTION

The present invention relates generally to methods and _ apparatus for the generation of chemical libraries of known composition, and more particularly to reaction block wash stations . BACKGROUND

The relationship between structure and function of molecules is a fundamental issue in the study of biological and other chemistry-based systems. Structure-function relationships are important in understanding, for example, the function of enzymes, cellular communication, and cellular control and feedback mechanisms. Certain macromolecules are known to interact and bind to other molecules having a specific three-dimensional spatial and electronic distribution. Any macromolecule having such specificity can be considered a receptor, whether the macromolecule is an enzyme, a protein, a glycoprotein, an antibody, an oligonucleotide sequence of DNA,

_ ₀ RNA or the like. The various molecules to which receptors bind are known as ligands.

A common way to generate such ligands is to synthesize libraries of ligands on solid phase resins. Since the introduction of solid phase synthesis methods for peptides,

__ oligonucleotides and other polynucleotides, new methods employing solid phase strategies have been developed that are capable of generating thousands, and in some cases even millions, of individual peptide or nucleic acid polymers using automated or manual techniques. These synthesis strategies,

, - which generate families or libraries of compounds, are generally referred to as "combinatorial chemistry" or "combinatorial synthesis" strategies.

To aid in the generation of combinatorial chemical libraries, scientific instruments have been produced which

__ automatically perform many or all of the steps required to generate such libraries. An example of an automated combinatorial chemical library synthesizer is the Model 396 MPS fully automated multiple peptide synthesizer, manufactured by Advanced ChemTech, Inc. ("ACT") of Louisville, KY. Another example of an automated combinatorial chemical library synthesizer is described in application serial no. 08/422,809, ₅ entitled "METHODS AND APPARATUS FOR THE GENERATION OF CHEMICAL LIBRARIES," filed April 17, 1995, assigned to the assignee of the present invention and incorporated herein by reference.

In such automated chemical library synthesizers, several different polymers are synthesized simultaneously, with a

. - different polymer being synthesized in each reaction chamber. One monomer is added to each monomer chain (i.e., polymer) before the addition of the next successive monomer to any polymer chain. Thus, each growing polymer chain usually contains the same number of monomers at the end of each

, _ synthesis cycle.

As is known to those skilled in the art, the process of combinatorial synthesis not only requires the introduction of a series of reagents including the desired monomers, but also requires washing, deblocking, capping, oxidation and other

_₀ steps as well. These steps must be performed regardless of the sequence in which the various monomers are introduced into the reaction chambers.

In the present automated combinatorial chemical library synthesizers, which incorporate pipetting workstations such as

₂₅ the TECAN 5032 (manufactured by TECAN AG, Feldbachstrasse 80, CH-8634 Hombrechtiken, Switzerland) , only one or two pipetting needles can be used to introduce the reagents or solvents used in the washing, deblocking, capping, oxidization, or other commonly performed steps. Since these steps could be performed

₃₀ simultaneously in all of the reactions chambers, the use of only one or two pipetting needles to introduce the appropriate reagents or solvents creates a significant increase in the length of time needed to synthesize a combinatorial chemical library. Accordingly, there remains a need in the art for an

_₅ apparatus and method for quickly and efficiently performing certain reaction steps (such as washing, deblocking, capping, etc.) simultaneously. SUMMARY

The preferred embodiments meet these needs by providing a multiple pipetting needle wash station which can introduce an _ appropriate reagent or solvent into all reaction chambers of a reaction block simultaneously. The wash station may also include a vortexing docking station which provides for secure registration of the reaction blocks, and provides for introduction of gases and liquids into the reaction blocks. An inert atmosphere in the reaction block can be maintained by a top and (optional) bottom seal.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a plan view of a pipetting work station. . _ Figure 2 is an isometric view of a reaction block and its associated hardware according to a preferred embodiment.

Figure 3 is a top view of the reaction block shown in Figure 2.

Figure 4 is a side cross-sectional view of the reaction -. block shown in Figure 2.

Figure 5 is a side cross-sectional view of the reaction block shown in Figure 2 including a removable bottom seal .

Figure 6 is a side cross-sectional view of the reaction block shown in Figure 2 including a microtiter plate. __ Figure 7 is a bottom view of the reaction block shown in Figure 2.

Figure 8 is a bottom plan view of the reaction block shown in Figure 2.

Figure 9 is a top view of a docking station according to ₃ _ a preferred embodiment.

Figure 10 is a cross sectional view of a connector in the docking station shown in Figure 9, inserted into a port in the reaction block shown in Figure 2.

Figure 11 is a cross sectional view of a connector in __ the docking station shown in Figure 9, inserted into a port having an open valve in the reaction block shown in Figure 2. Figure 12 is a cross sectional view of a connector in the docking station shown in Figure 9, inserted into a port having a closed valve in the reaction block shown in Figure 2.

Figure 13 is a plan view of a reaction block wash station according to a preferred embodiment.

Figure 14 is a top cross sectional view of the reaction block wash station shown in Figure 13.

Figure 15 is a cross sectional view showing a portion of a needle array including a needle manifold assembly as used in the reaction block wash station shown in Figure 13.

Figure 16 is a side view of the reaction block wash station shown in Figure 13, showing the needle arrays above the arrays of rinse tubes .

Figure 17 is a side view of the reaction block wash station shown in Figure 13, showing the needle arrays above „ _ the reaction blocks.

Figure 18 is a front view of the reaction block wash station shown in Figure 13, showing a portion of a needle array inserted into a reaction block.

Figure 19 is a front view of the reaction block wash station shown in Figure 13, showing a portion of a needle array inserted into a rinse tube array.

Figure 20 is a schematic diagram showing some of the wiring and plumbing connections used in the reaction block wash station shown in Figure 13.

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DETAILED DESCRIPTION

The structure and function of the preferred embodiments can best be understood by reference to the drawings. The reader will note that the same reference numerals appear in

--multiple figures. Where this is the case, the numerals refer to the same or corresponding structure in those figures . GENERAL OPERATION

Figure 1 is a plan view showing a portion of an automated pipetting work station 250 as may be used in a preferred

__ embodiment. Automated pipetting work station 250 may be a TECAN 5032 automated pipetting work station with one or more pipetting arms 252. Pipetting arm 252 attaches to needle assembly 20, which may be a coaxial needle assembly of the type disclosed in application serial no. 08/423,142 entitled "Pipetting Needle for Fluid Transfer Under Inert Atmosphere Operations," filed April 17, 1995, assigned to the assignee of the present invention and incorporated herein by reference. Coaxial needle assembly 20 includes a needle 22, a gas inlet port 30, and may also include an electrical connection 31. Work station 250 may also include pipetting needle rinse stations 70, which may be of the type disclosed in application - serial no. 08/423,141 entitled "Pipetting Needle Rinse Station" filed April 17, 1995, assigned to the assignee of the present invention, and incorporated herein by reference.

A locking reagent container rack 90 holds several containers 44 of reagents sealed from the outside air with septum seals 46. Rack 90 is preferably placed on the left side of work station deck 254. On the right side of work station deck 254 is a docking station 300 for receiving two reaction blocks 140. Each reaction block 140 contains an array of 48 reaction chambers 110 (see, e.g., Figure 2) . A

-₀ standard 96 well microtiter plate 302 may be mounted below reaction block 140 if product is to be removed from reaction chambers 110. REACTION BLOCK

Referring now to Figure 2, an isometric view of a

-_s reaction block 140 (and its associated hardware) according to a preferred embodiment is shown. Reaction block 140 is preferably machined out of 6061 aluminum (which is easily machinable and has good corrosion resistance) and then anodized for additional corrosion protection. Reaction block 140 could

₃₀ also be hard coat anodized and then impregnated with teflon. Additionally, reaction block 140 could be machined or molded from any suitable metal, engineering plastics, filled plastics, crystalline plastics, ceramics, machinable ceramics, or any other material that can withstand the temperature, pressure,

_₅ and chemical environment to which reaction block 140 will be exposed. If non-metallic materials are used, product reaction could be enhanced by the application of microwaves. If materials transparent to ultraviolet (UV) light are used, product could be cleaved from the synthesis support using UV light, and without the application of an acid or base.

Each end of reaction block 140 is preferably fitted with two pins 178 to facilitate handling by a robotic gripper (not shown) . Each side of reaction block 140 is preferably fitted with one pin 180 to facilitate securing reaction block 140 onto docking station 300. Robotic manipulation of reaction block 140 makes automation of the entire synthesis process

- -possible. For example, reagents could be introduced into reaction chambers 110 when reaction block 140 is locked onto docking station 300 of pipetting work station 250. Reaction block 140 could then be moved to a separate docking station 300, reaction block wash station 400 (see Figures 13 - 20) ,

--vortexing shaker table, heating or cooling chamber, or any other location or device useful in synthesis or the collection of material.

In a preferred embodiment, two types of reaction blocks capable of mating directly with a 96 well microtiter plate are

__n contemplated: the 48 reaction chamber 110 (and drain tube 138) positions of a first type of (or "A") block are offset from the 48 reaction chamber and drain tube positions of a second type of (or "B") block such that a type "A" and a type "B" block can fill every position in a standard 96 well microtiter plate.

The ability to deposit material directly into a 96-well

25 microtiter plate greatly reduces possible contamination and human error.

Reaction block 140 may be color coded for ease of identification, may have identification numbers 320 machined into or printed on the sides, and may also have a bar code 322 printed on the side for identification by machine.

Referring now to Figure 3, top portion 142 of reaction block 140 is shown. Top portion 142 preferably has an array of circular openings 144 arranged in a staggered grid. In a

-.preferred embodiment, reaction block 140 has 48 circular

35 openings 144. Openings 144 also preferably include a keying notch 145 (see Figure 2) which cooperates with a keying protrusion (not shown) on reaction chamber 110 and requires reaction chamber 110 to be in a predetermined orientation when inserted into opening 144.

The 48 openings 144 are divided into four chambers 146A through 146D of twelve openings 144 each. The chambers 146A- D are separated from each other by a plurality of raised beads 148, which are preferably machined into top portion 142.

Top portion 142 also includes four gas inlet ports 150A through 150D. Gas flows from gas inlet ports 150A-D, into

- - gas inlet chambers 152A through 152D, respectively (which are defined by raised sealing beads 148) . Gas then flows out through chamber exit ports 154A through 154D, respectively, and into chambers 146A through 146D, respectively. Gas flow to each chamber 146 can be individually controlled. For

- _ example, chambers 146A and 146C can be pressurized, without pressurizing chambers 146B and 146D.

When reaction chambers 110 are inserted and locked into place in openings 144, the top portions 120 of reaction chambers 110 are in approximately the same plane as the tops

-- of raised sealing beads 148.

Top surfaces 120 of reaction chambers 110 and raised sealing beads 148 are sealed by a sheet of septum material 153 (See Figure 2) . Septum 153 is preferably manufactured from 1/10" thermoplastic rubber (TPR) sheet. Septum 153 is

_₅ retained by a septum retainer plate 155, which is preferably fastened with six captive screw-type fasteners 156 which attach to openings 157. Fasteners 156 pass through openings 159 in septum 153, and screw into machined fastener openings 158.

₃₀ Reaction block 140 may be sealed from underneath with a bottom seal 220. An o-ring or quad ring 221 (see Figure 5) may be used to ensure a gas-tight seal. Bottom seal 220 may include a one-way valve 222 to allow pressure regulation. Bottom seal 220 is preferably fitted to reaction block 140

₃₅with screw-type fasteners 224. As can be seen in Figure 2, fasteners 224 pass through openings 226 in plate 155, through openings 228 in septum 153, through openings 230 in reaction block 140, and into openings 232 in bottom seal 220. Bottom seal 220 permits a desired atmosphere or pressure to be maintained within reaction block 140, allowing reaction block 140 to be moved from location to location (such as to a separate reaction block wash station 400, to a shaker table, heating or cooling chamber, or any other location or device useful in the synthesis or collection of material) without loss of such atmosphere or pressure. This can be especially useful in chemistries requiring long periods of time for reactions to take place. In these situations, such reactions can take place away from the pipetting work station, allowing the pipetting work station to be used for other purposes.

In a preferred embodiment, septum retainer plate 155 is machined from 6061 aluminum and anodized. However, retainer plate 155 could also be machined or molded from engineering plastics, ceramics, or any other material that can withstand the temperature, pressure, and chemical environment to which retainer plate 155 will be exposed.

Plate 155 is also preferably machined with 48 openings

162 positionally matched with openings 144 of reaction block •ø u

140 (and thus with openings 118 of reaction chambers 110) to accurately control the compression of the septum 153 between the tops 120 of reaction chambers 110, and plate 155.

Chambers 146 A through D include recessed waste basins

160 A through D, respectively, which are machined into top 25 portion 142 below the level of chamber exit ports 154A - D. This prevents a back flow of fluids from waste basins 160A - D into chamber exit ports 154A - D.

Referring now to Figure 4, a side cross-sectional view of reaction block 140 is shown. Reaction chambers 110 are held in place by machined annular steps 170 (which define openings 171), and machined annular beads 172. S-shaped trap tube 136 and drain tube 138 are held in place by a friction fit against walls 174 and openings 176 (See Figures 7 and 8) .

Steps 177 are machined into the bottom of reaction block 140 to allow reaction block 140 to mate directly with a standard 96-well microtiter plate 302 (see, e.g., Figures 1 and 6) . Steps 177 also allow mating and sealing with bottom seal 220 (see Figures 2 and 5) .

Referring now to Figures 7 and 8, bottom and plan views of reaction block 140 are shown. The underside of reaction _ block 140 includes a generally planar surface 190 which includes a plurality of openings 171 and 176, discussed above.

Openings 176 include a relatively larger portion 192, which accommodates drain tube 138, and a relatively smaller portion 194, which accommodates s-shaped trap tube 136.

- - The underside of reaction block 140 also includes four gas ports 196A through 196D located on bottom surface 198. Ports 196A-D connect to gas inlet ports 150A-D (See Figure 3) , respectively, through machined tunnels (not shown) in reaction block 140.

- _ Also included on bottom surface 198 is a gas inlet port

200 which connects to a gas outlet port 201 via a machined tunnel (not shown) . This allows pressure on the underside of reaction block 140 to be independently controlled when it is sealed by bottom seal 220 (see Figures 2 and 5) .

__ Bottom surface 198 also includes two gas or liquid ports 202A and 202B. The interior of reaction block 140 is preferably machined to include passages (not shown) in which heating or cooling gas or liquid can flow if desired. Gas or liquid can enter port 202A and exit through port 202B, or vice

_{2 ς} versa. If reaction block 140 is made of material having high thermal stability or thermal mass such as 6061 aluminum, this arrangement allows reaction block 140 to be quickly and efficiently heated or cooled for chemistries that require such heating or cooling.

,₀ Ports 196A-D, 200 and 202 may also serve as guide pin holes to position reaction block 140 properly on docking station 300 (see, e.g., Figures 1, 9, and 13) .

Finally, a bar magnet 204 may be mounted flush with surface 198. Bar magnet 204 serves to activate magnetic reed

_₅ switch 314 mounted in docking station 300 (see Figure 9) . As will be discussed below, one or more reed switches can be used to prevent the operation of work station 250 or reaction block wash station 400 (see Figures 13 - 20) unless one or more reaction blocks 140 are properly in place. DOCKING STATION

Referring now to Figures 1, 9, and 13, a docking station 300 according to a preferred embodiment is shown. Docking station 300 preferably includes two stations, 306A and 306B, for receiving reaction blocks 140 of Type "A" and Type "B", respectively, as discussed above. As is known to those skilled in the art, docking station 300 may also be fitted with the

- - proper motor, gears, and other elements (not shown) necessary for docking station 300 to act as a vortexing shaker, and preferably as a vortexing shaker having a fixed displacement and variable speed.

Docking station 300 also preferably includes three locking linkages 304 for locking onto pins 180 on reaction blocks 140. Each station 306 includes gas outlet connectors 308A through 308D which connect to ports 196A through 196D, respectively in reaction block 140 (see Figure 7) . Each station 306 also includes two coolant or heating fluid (i.e., _n gas or liquid) connectors 310A and 310B. Figure 1 shows b U fluid lines 320A and 320B attached to connectors 310A and 310B, respectively. Although not shown in Figures 1, 9, and 13, controllable fluid lines attach to each connector shown in docking station 300. Connectors 310A and 310B connect to

₅ _ ports 202A and 202B, respectively in reaction block 140 (See Figure 7) . A gas outlet connector 312 which connects to gas inlet port 200 of reaction block 140 is also included in each station 306.

Finally, stations 306A and 306B each include a magnetic

-- reed switch 314A and 314B, respectively, which senses the presence of magnet 204 on reaction block 140. Station 306A, and more specifically the placement of connectors 312, 310A, and 310B, is arranged such that only an A-type reaction block 140 can be fully inserted and locked into position.

, _ Similarly, station 306B, and more specifically the placement of port 312, is arranged such that only a B-type reaction block 140 can be fully inserted and locked into position. Referring now to Figure 10, a cross sectional view of a connector 308A inserted into port 196A of reaction block 140 is shown. Although only the interface between connector 308A and 196A will be discussed, it will be understood that similar interfaces are preferably included in other connections between reaction block 140 and docking station 300. In a preferred embodiment, connector 308A is inserted into port 196A. In this fashion, connector 308A acts as a guide pin to ensure proper alignment of reaction block 140 with station 306A. A gas-tight seal between connector 308A and port 196A is preferably provided by quad ring 330. A quad ring is preferred over a standard o-ring because a quad ring has less tendency to adhere to surfaces when connector 308A is removed from port 196A.

_. _ Referring now to Figures 11 and 12 an alternative embodiment of port 196A is shown. In operations where inert or other atmosphere must be maintained, a normally closed valve, such as schraeder valve 360 may be placed in port 196A. Schraeder valve 360 may be replaced with a bi-directional

-- elastomeric valve. In operation, connector 308A is inserted into port 196A and engages pin 362 of schraeder valve 360. Connector 308A also forms a seal against quad ring 330. Gas flows out of opening 364 and through schraeder valve 360.

When connector 308A is removed from port 196A, pin 362

₂₅ of schraeder valve 360 moves downward, creating a gas-tight seal. Again, this allows reaction block 140 to be moved from place to place while maintaining a desired atmosphere.

Pipetting work station 250 (see Figure 1) and reaction block wash station 400 (see Figure 13) are preferably

₃ - constructed such that operation of the work station 250 or wash station 400 cannot take place unless magnetic reed switches 31 A and 314B detect the presence of one or both reaction blocks 140. That is, pipetting work station 250 and reaction block wash station 400 will not operate unless

-- reaction blocks 140 are properly mounted in stations 306A and 306B. REACTION BLOCK WASH STATION Referring now to Figure 13, a plan view of reaction block wash station 400 is shown. Wash station 400 includes a docking station 300 of the type discussed above in part with respect to Figures 1 and 9. Docking station 300 is _c preferably adapted to receive a type A reaction block 1 0A and a type B reaction 140B. Docking station 300 is mounted on platform 402, along with a first array of 404A of rinse tubes and a second array 404B of rinse tubes.

Wash station 400 also includes an assembly 406 which preferably includes an array 408A of 48 non-coring luer lock needles and a second array 408B of 48 non-coring luer lock needles (see, e.g., Figure 16) . Assembly 406 is slidably mounted to wash station 400 along slot 410 in wall 412, and may also be slidably mounted in a slot (not shown) in wall 414. Assembly 406 (and thus arrays 408A and 408B) is movable along the X axis so that arrays 408A and 408B may be positioned over reaction blocks 140A and 140B or over rinse tube arrays 404A and 404B. Arrays 408A and 408B are also movable up and down along the Z axis so that they may be raised - - or lowered.

The motion of assembly 406 and needle arrays 408A and

408B may be achieved using any means known to those skilled in the art. For example, needle arrays 408A and 408B are preferably moved up and down along the Z axis through the use of a lead screw driven by a servo motor (not shown) . Assembly 25

406 is preferably moved side to side along the X axis using an air pressure or hydraulic cylinder 451 (see Figure 20) . Cylinder 451 is preferably a band cylinder of the type manufactured by the Tol-o-Matic Corporation of Minneapolis,

-- Minnesota. A band cylinder is preferred because it can provide a large linear motion relative to its overall length.

Alternatively, assembly 406 could be moved along the X axis by a stepper motor or a servo controlled motor. However, the use of such motors would require a much more complex

__ arrangement, including pulleys, timing belts, etc.

Referring now to Figure 14, a top, partially cut away view of wash station 400 is shown. To prevent injury to the operator of the wash station, a hardware interlock including a "light curtain" which passes around the periphery of platform 402 can be used. Such a light curtain operates in a manor well known to those skilled in the art. For example, a light _ source 416 generates a light beam 418 which is reflected around the periphery of platform 402 by mirrors 420. Reflected light beam 418 is then detected by a detector 422. If the light curtain is interrupted, the wash station ceases to function until reset by the operator. This reset operation is preferably performed when the operator presses a reset button (not shown) .

The hardware interlock may also include a manually operated emergency stop button (not shown) , which also causes the wash station to cease functioning until reset by the operator, preferably with the same reset button discussed above.

Wash station 400 preferably also includes four servo motor controlled pumps 424 and eight solenoid valves 425 (see Figure 20) to deliver metered amounts of one of four solvents -- to needle arrays 408A and/or 408B from remote solvent reservoirs (not shown) . Needle arrays 408A and 408B can be individually controlled. This function will be discussed further below.

The solvent reservoirs are preferably stainless steel

__ tanks (not shown) which are pressurized with helium.

Undesirable gasses dissolved in the solvents are removed by sparging the solvents with helium gas. After the undesirable gasses have been vented, the solvents remain pressurized with helium, preferably to a pressure of about 5 psig. This

₃ - pressurization reduces the possibility that cavitation (i.e., bubble formation) will occur when the solvents are pumped by pumps 424.

Referring now to Figure 15, a side cross sectional view of a needle array 408 is shown. As discussed above, each

₃ _ array 408 preferably includes 48 non-coring luer lock needles 426. Needles 426 are attached to luer connectors 428 which are mounted in wall 430. Needles 426 receive fluid (i.e., either liquid or gas) from distribution manifold 432 via tubes 434. Distribution manifold 432 includes a cavity 436 which is communication with each tube 434. In a preferred embodiment, each distribution _ manifold 432 includes four solvent inlet ports 438 (only two are shown in Figure 13) which are in communication with cavity 436 via one way valves 440. Inlet ports 438 are driven by pumps 424 (see Figure 14) .

Each distribution manifold 432 preferably also includes a

_{1 n} nitrogen inlet line 442, which is in communication with cavity 436 via one way valve 444. This allows nitrogen to pass through or purge needles 426 if desired.

Figure 16 is a partial side view of wash station 400 showing assembly 406 and needle arrays 408A and 408B

- - positioned over rinse tube arrays 404A and 404B. Needles 426 in needle arrays 408A and 408B may be washed by lowering the needles 426 along the Z axis into rinse tubes 446 of rinse tube arrays 404A and 404B. Rinse tubes 446 are preferably closed at the bottom and have an open lip at the top. When

-- cleaning solution is pumped through needles 426, the solution flows into rinse tubes 446 and then out the top of rinse tubes 446 into a waste receptacle (not shown) .

Figure 17 is a side view of wash station 400 showing assembly 406 and needle arrays 408A and 408B positioned over

₅_ reaction blocks 104A and 104B. To deliver solvents into the reaction chambers of reaction blocks 140A and 140B, needle assemblies 408A and 408B are lowered along the Z axis until the needles 426 enter the reaction chambers within reaction blocks 140A and 140B. At that time, the desired solvent may

-- be pumped through needles 426 and simultaneously injected into each reaction chamber within reaction blocks 140A and 140B. Needle arrays 408A and 408B are then removed from reaction blocks 140A and 140B.

As discussed above, docking station 300 can be made to vortex at varying speeds. This allows reaction blocks 140A and 140B to be agitated, if that is desired for the particular reaction step being performed. Of course, the needle arrays 408A and 408B must be at a sufficient elevation before the reaction blocks 140 are vortexed to prevent bending of the needles. A hardware interlock (not shown) may be used to prevent vortexing while the needles are within the reaction _ blocks.

Figure 18 is a front view of wash station 400 showing needle array 408B inserted into reaction block 140B, as discussed above.

Figure 19 is a front view of wash station 400 showing needle array 408B inserted into rinse tube array 404B, as discussed above.

Figure 20 is a wiring and plumbing schematic of wash station 400 according to a preferred embodiment. As discussed above, four solvent pumps 424 and eight solenoid valves 425

- _ are used to feed manifold assemblies 432. Nitrogen line 442 feeds manifold assemblies 432. Nitrogen lines 452A and 452B feed stations 306A and 306B. Programmable shaker motor 448 is used when docking station 300 acts as a vortexing shaker table. Z axis motor 450 is used to move needle arrays 408A

-_ and 408B up and down along the Z axis. Cylinder 451 is used to move needle arrays 408A and 408B along the X axis.

Wash station 400 is preferably computer controlled. In a preferred embodiment, the operator will be able to program "wash profiles" for various purposes. Each wash profile can

₂₅ vary as to:

1. Type of wash solvent;

2. Volume of solvent selected;

3. Speed with which solvent is dispensed;

4. Time of agitation; ₃₀ 5. Speed of agitation;

6. Activation of nitrogen purge; and

7. The number of cycles of any of the above parameters.

EXAMPLE OF OPERATION

₃₅ The many features of the preferred embodiments described above facilitate the relatively quick and efficient generation of chemical libraries. In the following discussion, a synthesis operation involving a type "A" reaction block 140 will be discussed. However, it will be understood that the following discussion will apply equally for a type "B" block as well .

In a typical operation, a synthesis support such as solid 5 phase resin is deposited onto each frit 124 in reaction chambers 110. Reaction block 140 is then assembled as shown in Figure 2. Bottom seal 220 may be mounted if reaction block 140 must be moved from place to place while maintaining - - a desired atmosphere or pressure.

Reaction block 140 may then be manually or robotically inserted into station 306A of docking station 300 on work station 250 (see Figure 1) . At this point, microtiter plate 302 is not located in station 306A. Locking linkages 304

- _ then grip pins 180, locking reaction block 140 into place. A

15 type "B" reaction block may be simultaneously mounted in station 306B.

Pipetting work station 250 then operates under computer control to deliver the chosen combination of reagents into -. reaction chambers 110. Specifically, pipetting needle 22 (as controlled by pipetting arm 252) is used to transfer reagents from septum 46 sealed containers 44 into septum 253 sealed reaction chambers 110. The interior and exterior of pipetting needle 22 may be cleaned as necessary in rinse stations 70.

- _ At any time that reaction block 140 is mounted in station

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306A, reaction block 140 may be heated or cooled, pressurized with inert gas, or vortexed as described above.

For reactions that take a considerable amount of time or that require common reagents, reaction block 140 may be __ manually or robotically moved to another docking station 300 such as wash station 400 (which operates as described above) , or to some other location while the reactions are taking place. After the synthesis of the desired products has been completed and the appropriate washing steps performed, the products may

_ _c be cleaved from the synthesis supports using the appropriate

35 reagents. These reagents may be applied at work station 250, or they may be applied robotically at some other location such as wash station 400. If bottom seal 220 had been mounted, it is then removed, and a microtiter plate 302 is then inserted beneath reaction block 140 in station 306A. Reaction chambers 110 are then pressurized, forcing the product out drain tubes _ 138 and into alternate wells of microtiter plate 302. Microtiter plate 302 is then moved to station 306B, and inserted beneath a type "B" reaction block 140. Product is then deposited into the alternate empty wells of microtiter plate 302 as discussed above. Again, this process allows

- _ product to be deposited directly into the wells of a standard microtiter plate, without requiring an intermediate step.

The present invention has been described in terms of a preferred embodiment. The invention, however, is not limited to the embodiment depicted and described. Rather, the scope of

₁₅ the invention is defined by the appended claims.

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5

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5

Claims

WHAT IS CLAIMED IS:

1. A reaction block wash station, comprising: a docking station for removably receiving a reaction block, the reaction block having an array of reaction chambers _ with a predetermined configuration; a movable array of pipetting needles arranged to match the configuration of the reaction chambers; and an array of wash tubes arranged to match the configuration of the reaction chambers and the pipetting «, - needles; the needle array in communication with a supply of solvent, and movable horizontally so as to be positioned over the reaction block or the array of wash tubes; the needle array also movable vertically so as to be _ positioned within the array of wash tubes or the reaction chambers.

2. The reaction block wash station of claim 1 wherein solvent is pumped through all needles of the needle array -- simultaneously.

3. The reaction block wash station of claim 1 wherein the needle array is in communication with a supply of gas.

_ _c 4. The reaction block wash station of claim 3 wherein gas is pumped through all needles of the needle array simultaneously.

5. The reaction block wash station of claim 1 wherein each needle in the needle array is a non-coring needle.

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6. The reaction block wash station of claim 5 wherein each needle in the needle array is in communication with a manifold.

7. The reaction block wash station of claim 6 wherein the ₃₅ manifold includes a plurality of fluid valves.

8. The reaction block wash station of claim 7 further comprising a plurality of pumps, each pump for supplying a predetermined solvent to the manifold via a predetermined one of the fluid valves in the manifold.

_

9. The reaction block wash station of claim 8 wherein the

5 manifold includes a gas valve.

10. The reaction block wash station of claim 10 further comprising a supply of pressurized gas for supplying gas to the 0 manifold via the gas valve in the manifold.

11. The reaction block wash station of claim 10 wherein the movement of the needle array and the delivery of solvent and gas into the manifold is computer controlled. 5

12. The reaction block wash station of claim 1 wherein the reaction block has a plurality of gas inlet ports.

13. The reaction block wash station of claim 12 wherein the - docking station comprises: a platform including a cavity for removably receiving the reaction block; a plurality of gas outlet connectors coupled to the gas inlet ports of the reaction block; ₅ a reed switch which detects the presence of the reaction block; and a linkage which locks the reaction block into the cavity.

_ 14. The reaction block wash station of claim 13 wherein the reaction block includes a bar magnet, and wherein the reed switch detects the presence of the bar magnet.

15. The reaction block wash station of claim 14 further ₅ including a heating or cooling fluid outlet connector coupled to a heating or cooling fluid inlet port on the reaction block.

16. The reaction block wash station of claim 15 wherein the platform includes a first cavity of a first type for receiving a first reaction block of a first type, and a second cavity of a second type for receiving a second reaction block of a second type.

17. The reaction block wash station of claim 16 wherein the gas outlet connectors fit into the gas inlet ports of the reaction blocks.

18. The reaction block wash station of claim 17 wherein the gas outlet connectors are sealed against the gas inlet ports with quad rings.

19. The reaction block wash station of claim 18 wherein the platform acts as a vortexing shaker.

20. The reaction block wash station of claim 1 further including a light curtain which is reflected around the docking station and the array of rinse tubes.

21. The reaction block was station of claim 20 wherein the reaction block wash station is rendered inoperative if the light curtain is broken.

22. The reaction block wash station of claim 1 further including an emergency stop button, wherein the reaction block wash station is rendered inoperative if the emergency stop button is activated. 0

23. A reaction block wash station, comprising: a first docking station for removably receiving a first reaction block, the first reaction block having an array of reaction chambers with a predetermined configuration; _ a second docking station for removably receiving a second reaction block, the second reaction block having an array of reaction chambers with a predetermined configuration; a first movable array of pipetting needles arranged to match the configuration of the reaction chambers reaction chambers in the first reaction block; a second movable array of pipetting needles arranged to match the configuration of the reaction chambers in the second reaction block; a first array of wash tubes arranged to match the configuration of the reaction chambers in the first reaction block and the first array of pipetting needles; and - a second array of wash tubes arranged to match the configuration of the reaction chambers in the second reaction block and the second array of pipetting needles; the first needle array in communication with a supply of solvent, and movable horizontally so as to be positioned , X3_ over the first reaction block or the first array of wash tubes; the second needle array in communication with a supply of solvent, and movable horizontally so as to be positioned over the second reaction block or the second array of wash tubes; ₂_ the first needle array also movable vertically so as to be positioned within the first array of wash tubes or the reaction chambers in the first reaction block; the second needle array also movable vertically so as to be positioned within the second array of wash tubes or the ₂₅ reaction chambers in the second reaction block; the first needle array and the second needle array being individually controllable.

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