U.S. patent application number 10/101759 was filed with the patent office on 2002-09-19 for devices and methods for accessing reaction vessels.
This patent application is currently assigned to Argonaut Technologies, Inc.. Invention is credited to Hughes, Jan, Kilcoin, Christopher, Long, Terry, Wasson, James.
Application Number | 20020132366 10/101759 |
Document ID | / |
Family ID | 27378401 |
Filed Date | 2002-09-19 |
United States Patent
Application |
20020132366 |
Kind Code |
A1 |
Kilcoin, Christopher ; et
al. |
September 19, 2002 |
Devices and methods for accessing reaction vessels
Abstract
Devices and methods are provides for delivering fluids into
reaction vessels. The present device is an interface head which
allows a user to add reagents and wash solvents to a reaction
vessel. Typically, the interface head can engage a plurality of
these reaction vessels mounted in a cassette or frame and is
adapted to removably engage passages leading into the plurality of
passageways in the head which are fluidly coupled to the reaction
vessel. In one embodiment, the interface head has a septa valve
which opens and closes inlets of the plurality of passageways. The
septa valve comprises an elongate member with a septum portion and
a plurality of septum ports. The elongate member is slidable
between a first position wherein at least one inlet of the
passageways in the interface head is sealed by the septum portion
and a second position wherein said at least one inlet is aligned
with one of the ports to allow delivery of materials from the inlet
into the reaction vessel. The septum portion is penetrable by
needles and thus allows access for needle/syringe type delivery
devices.
Inventors: |
Kilcoin, Christopher; (Los
Altos Hills, CA) ; Long, Terry; (Tucson, AZ) ;
Hughes, Jan; (Belmont, CA) ; Wasson, James;
(Los Altos, CA) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
Argonaut Technologies, Inc.
San Carlos
CA
|
Family ID: |
27378401 |
Appl. No.: |
10/101759 |
Filed: |
March 19, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10101759 |
Mar 19, 2002 |
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09378664 |
Aug 20, 1999 |
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6395235 |
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60116908 |
Jan 22, 1999 |
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60097511 |
Aug 21, 1998 |
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Current U.S.
Class: |
436/174 ;
422/400; 436/180 |
Current CPC
Class: |
B01J 2219/00333
20130101; B01J 2219/00396 20130101; C40B 60/14 20130101; B01J
2219/00283 20130101; B01J 2219/00398 20130101; Y10T 137/87249
20150401; B01J 2219/00308 20130101; B01J 2219/00418 20130101; Y10T
436/25 20150115; Y10T 436/2575 20150115; B01J 2219/00389 20130101;
B01J 2219/00423 20130101; B01J 2219/00369 20130101; G01N 35/10
20130101; B01J 2219/00484 20130101; B01J 2219/00351 20130101; B01J
19/0046 20130101; B01J 2219/00495 20130101 |
Class at
Publication: |
436/174 ;
436/180; 422/102; 422/103; 422/104 |
International
Class: |
G01N 001/18 |
Claims
What is claimed is:
1. A device for use in simultaneously delivering fluids to a
plurality of reaction vessels each having an first upper port and a
second upper port, said device comprising: an interface head
adapted to removably engage a plurality of passages each leading to
said first upper port on each of said reaction vessels; a plurality
of infusion passages in said interface head each having outlets
adapted to be positioned to feed into said plurality of reaction
vessels; and a common infusion passage defined within said
interface head, said common passage fluidly couplable to said
plurality of infusion passages for simultaneously delivering fluid
into said plurality of reaction vessels.
2. A device as in claim 1 wherein the interface head further
comprises an interface tube adapted to form a radial seal with said
passage leading to a first upper port of the reaction vessel, said
tube fluidly coupled to said infusion passage downstream of said
common passage.
3. A device as in claim 2 wherein said interface tube comprises a
non-piercing member.
4. A device as in claim 1 wherein the plurality of infusion
passages are adapted to be positioned to feed into said reaction
vessels, defining a fluid delivery path into the interior of the
reaction vessel from said common passage, through one of the
infusion passages, and through a reaction vessel tube extending to
the bottom of reaction vessel.
5. A device as in claim 1 wherein the interface head further
comprises a membrane valve covering said common passage, said valve
activated by gas pressure, wherein said valve simultaneously
controls fluid flow through all of said infusion passages.
6. A device as in claim 1 wherein: the common passage comprises a
groove on a surface of a manifold in said interface head; the
plurality of inlet passages having openings on said surface of the
manifold; a layer of chemically inert material covering said
surface of the manifold, said layer movable between a first
position wherein the common passage and plurality of inlet passages
are in fluid connection and a second position wherein the passages
are sealed from one another.
7. A device as in claim 1 wherein the interface head further
comprises: a plurality of extraction passages defined within said
interface head, wherein each of said extraction passages is coupled
to one of said downwardly extending tubes.
8. A device as in claim 1 wherein the interface head further
comprises: a plurality of vent passages having outlets positioned
to open into said plurality of reaction vessels; a common vent
passage defined by said interface head, said common vent passage
fluidly couplable to said plurality of vent passages for venting
gas from said plurality of reaction vessels; and a plurality of
individually controllable vent valves controlling fluid connection
between the common vent passage and one of said vent passages.
9. A device as in claim 1 wherein the interface head further
comprises: a plurality of individually actuatable valves
controlling flow from said reaction vessels (or perhaps from the
vent ports).
10. A device as in claim 1 wherein the interface head is adapted to
define a plurality of fluid delivery pathways into the interior of
said reaction vessels, said interface head having a plurality of
tubular structures which are adapted to slidably engage a portion
of a passage downstream from the interface head and connecting to
the first ports of the reaction vessel, said tubular structures
forming circumferential seals, said interface head removable from
said pathway downstream of the interface head.
11. A device for use in delivering reagents to a reaction vessel
having an first upper port, a second upper port, and an interior,
said device comprising: an interface head having a plurality of
inlet passageways, said interface head adapted to engage a passage
leading to the first upper port of said reaction vessel; and a
valve in said interface head for simultaneously controlling fluid
flow to a plurality of inlet passageways.
12. A device as in claim 11 wherein said valve comprises a membrane
valve controlling flow from a common passage in the interface head
to said plurality of inlet passageways.
13. A device as in claim 11 further comprising a manual
injection/input passageway coupled to said inlet passageway in said
interface head.
14. A device as in claim 11 further comprising a septa valve having
an elongate member with an access port and a septum, said elongate
member slidable between a first position aligning an opening in
said interface head with said access port and a second position
where said septum covers said opening.
15. A device as in claim 11 wherein each of said inlet passageways
contain a tubular member for transporting material through said
passageways.
16. A device as in claim 11 wherein said device is adapted to be
removed from the reaction vessels during processing.
17. A method for filling a plurality of reaction vessels during one
fill cycle, said method comprising: flowing fluid along a common
passage to said plurality of reaction vessels, wherein said common
passage has a plurality of individual passageways opening into said
plurality of reaction vessels; filling said reaction vessels in a
substantially even manner by using back pressure in the reaction
vessels to direct flow to the reaction vessels with the least
amount of fluid and back pressure; relieving back pressure in said
reaction vessels by opening reaction vessel vent valves to allow
the reaction vessels to continue filling with fluid.
18. A method as in claim 17 wherein said relieving of back pressure
occurs when flow rate into said reaction vessels has reached a rate
of about 0.1 ml/min.
19. A method as in claim 17 wherein said common passage has a valve
controlling flow into each of said individual passageways and said
filling step comprises a plurality of opening and closing of said
valves during one fill cycle to maintain even fluid flow the
reaction vessels.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the following
Provisional Patent Applications: Systems and Methods for Accessing
Reaction Vessels, Application No. 60/097,511, filed Aug. 21, 1998;
Devices and Methods for Accessing Reaction Vessels, Application No.
60/116,908, filed Jan. 22, 1999, the disclosures of which are
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The standard method for searching for new chemical compounds
which can effectively modulate biological processes employs the
screening of pre-existing compounds in assays which have been
designed to test particular properties of the compound being
screened. Similarly, in designing compounds having desired
physiochemical properties for general chemical applications,
numerous compounds must be individually prepared and tested.
[0003] To reduce the time and expense involved in preparing and
screening a large number of compounds for biological activity or
for desirable physiochemical properties, technology has been
developed for providing libraries of compounds for the discovery of
lead compounds. Current methods for generating large numbers of
molecularly diverse compounds focus on the use of solid phase
synthesis. The generation of combinatorial libraries of chemical
compounds by employing solid phase synthesis is well known in the
art. For example, Geysen, et al. (Proc. Natl. Acad. Sci. USA, 3998
(1984) describe the construction of multi-amino acid peptide
libraries; Houghton, et al. (Nature, 354, 84 (199 1) and PCT Patent
Pub. No. WO 92/09300) describe the generation and use of synthetic
peptide combinatorial libraries for basic research and drug
discovery; Lam, et al. (Nature, 354, 82 (199 1) and PCT Patent Pub.
No. WO 92/0009 1) describe a method of synthesis of linear peptides
on a solid support such as polystyrene or polyacrylamide resin.
[0004] The growing importance of combinatorial chemistry as an
integral component of the drug discovery process has spurred
extensive technological and synthetic advances in the field
(Thompson, L. A.; Ellman, J. A. (1996) Chem. Rev. 96,555-600).
Founded in peptide synthesis devised by Merrifield, solid phase
chemistry has emerged as the preeminent method for construction of
small molecule combinatorial libraries (see e.g. Merrifield, R B.
(I 963) J. Am. Chem. Soc. 85, 2149-2154; (a) Terrett, N. K.;
Gardner, M.; Gordon, D. W.; Kobylecki, R. J.; Steele, J.
(1995)Tetrahedron 51(30), 8135-8173. (b) Gordon, E. M.; Barrett, R.
W.; Dower, W. J.; Fodor, S. P. A.; Gallop, M. A. (1994) J. Med
Chem. 37,1385-1401.).
[0005] Unfortunately, the generation of chemical compounds for
combinatorial chemical libraries is a labor intensive process.
Working with numerous reaction vessels concurrently is very
difficult and time consuming. In the past, multiple solid phase
reactions were conducted by heating a substrate attached to resin
beads with appropriate reagents and solvents in a test tube
immersed in a hot oil bath with a rotating magnetic stir bar.
Draining was accomplished by pouring the contents of the test tube
through a filter. Back and forth operation between reacting and
draining operations was very tedious and potentially exposed the
reaction mixture to air. Certain chemical processes also required
that the chemical reagents be kept under an inert or anhydrous
atmosphere to prevent reactive groups from reacting with molecular
oxygen, water vapor, or other agents commonly found in air.
Accordingly, there is a need for a device which would provide
heating and/or cooling, mixing, a closed environment for moisture
sensitive and air sensitive chemistries, easy draining, rapid
liquid metering, and rinsing of a plurality of reaction
vessels.
[0006] While certain chemical synthesizers are known in the art,
these synthesizers fail to provide the desired features necessary
to efficiently generate large numbers of chemical compounds.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to an apparatus which is
useful for the synthesis of chemical compounds, for example, for
the preparation of multiple discrete compounds for combinatorial
libraries of compounds. The present invention is useful for
developing new drugs and chemical entities. The invention is useful
for rapidly generating and systematically synthesizing large
numbers of molecules that may vary in their chemical structure or
composition. The invention is further useful for randomly
generating a large number of candidate compounds, then later
optimizing those compounds which exhibit the most desirable
properties
[0008] The present invention provides a interface head which allows
a user to add reagents and wash solvents to a reaction vessel.
Typically, the interface head can engage a plurality of these
reaction vessels mounted in a cassette or frame and is adapted to
removably engage passages leading into the reaction vessel. The
interface head allows a user to manually inject materials into the
plurality of passageways in the head which are fluidly coupled to
the reaction vessel. The interface head has a septa valve which
opens and closes inlets of the plurality of passageways. The septa
valve comprises an elongate member with a septum portion and a
plurality of septum ports. The elongate member is slidable between
a first position wherein at least one inlet of the passageways in
the interface head is sealed by the septum portion and a second
position wherein said at least one inlet is aligned with one of the
ports to allow delivery of materials from the inlet into the
reaction vessel. The septum portion is penetrable by needles and
thus allows access for needle/syringe type delivery devices.
[0009] Advantageously, the interface head may be manually operated
to provide ease of use for operators. The interface head, of
course, may also be adapted to be used with automated systems, such
as mounted on a robotic manipulator. The interface, however, may
also be used to add reagents to reaction vessels in situations
where reagents in an automated procedure were left out or
additional solvent washes are needed. The interface head may also
be adapted to extract finished material from within reaction
vessels. Guide pins may be provided to assist in the alignment of
the interface head with a cassette or housing used to contain the
reaction vessels. In some embodiments, the device is essentially a
manifold having a septa valve providing access to a pipet or
reagent injector, a coupling tube to interface with a passage
leading to the reaction vessel, and a connector for actuating the
valve of the reaction vessel.
[0010] In preferred embodiments, the interface head of the present
invention allows for simultaneous introduction of wash fluids into
a plurality reaction vessels. Typically, the reaction vessels each
having a first upper port and a second upper port. The interface
head is adapted to removably engage a plurality of passages each
leading to the first upper port on each of the reaction vessels. A
plurality of infusion passages in the interface head each have
outlets adapted to be positioned to feed into the reaction vessels.
Fluid introduced into a common infusion passage defined within the
interface head may be simultaneously delivered into the infusion
passages and into the reaction vessels. The interface head
preferably has an interface tube adapted to form a radial seal with
the passage leading to a first upper port of the reaction vessel,
where the infusion passage is downstream of the common passage.
Flow from the common passage into the infusion passages is
preferably controlled by a membrane valve covering the common
passage. The common passage is typically a groove on a surface of a
manifold in the interface head. The interface head may also include
a plurality of vent passages and a common vent passage defined by
the interface head to remove materials from the plurality of
reaction vessels.
[0011] In another aspect of the present invention, a method is
provided for providing a substantially equal distribution of fluids
to a plurality of reaction vessels during one fill cycle. The
method includes flowing fluid along a common passage to the
plurality of reaction vessels, where the common passage has a
plurality of individual passageways opening into the reaction
vessels. The reaction vessels are filled by using back pressure in
the reaction vessels to direct flow to the reaction vessels with
the least amount of fluid and back pressure. Back pressure in the
reaction vessels are relieved by opening reaction vessel vent
valves to allow the reaction vessels to continue filling with
fluid. Without doing so, the back pressure may substantially slow
delivery of fluids into the reaction vessels.
[0012] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIGS. 1A-1B show an interface head according to the present
invention in use with a cassette holding a plurality of reaction
vessels;
[0014] FIG. 2 is a perspective view of a cassette mounted on a
heating and agitation unit;
[0015] FIG. 3A is a cross-section of the interface head of FIGS.
1A-1B;
[0016] FIG. 3B is a partial cross-section of the interface head and
cassette when they are mated together;
[0017] FIGS. 4-5 provide perspective views of the interface head of
FIGS. 1A-1B;
[0018] FIGS. 6-10 provide views of tubular members according to the
present invention used with the interface head;
[0019] FIGS. 11-12 show an alternative embodiment of the interface
head dedicated for extracting materials from reaction vessels;
[0020] FIGS. 13-18 shows various views of a manifold used in the
interface head of FIGS. 1A and 1B;
[0021] FIG. 19 is a perspective view of a housing for use with the
heating and agitation unit of FIG. 2;
[0022] FIGS. 20-21 are perspective views of an interface head for
both infusion and extraction;
[0023] FIGS. 22-23 are cross-section views of the interface head
depicting the function of the interface head of FIG. 20;
[0024] FIGS. 24-25 show a manifold used in an interface head of
FIG. 20; and
[0025] FIGS. 26-30 shows various views of an exemplary embodiment
of an interface head according to the present invention.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0026] The present invention is directed to the synthesis of
chemical compounds, such as for the generation of combinatorial
chemical libraries. Specifically, the present invention provides an
apparatus by which any variety of single compounds or combinatorial
libraries may be created. The reaction apparatus of the present
invention provides numerous advantages over known instrumentation.
With large numbers of samples to process, the present apparatus
facilitates the synthesis by allowing for common introduction of
reagents and the simultaneous washing of a plurality of reaction
vessels. This processing is preferably performed under an inert
atmosphere in the reaction vessels. The present invention may also
provide an agitator for uniformly and gently mixing the reaction
media. Constant and evenly distributed heating and cooling may be
provided during synthesis.
[0027] To facilitate the ease of operation, certain functions of
the present invention, such as agitation of the reaction mixture,
heating and cooling of the reaction vessel, inlet of inert
atmosphere, introduction of reagents and solvents, rinsing and
draining of reaction mixtures, and the like are preferably
conducted by robotic automation or computer control. Accordingly,
certain embodiments of the present invention are directed to the
use of the apparatus which is partially or entirely conducted by
robotic automation or under computer control.
[0028] As will be readily apparent to one skilled in the art the
present invention is useful for the solid phase synthesis of
organic compounds, including peptides. This device may be used for
both solid phase chemistry and liquid-liquid chemistry, but solid
phase chemistry is preferred. Alternatively, the present invention
may be employed for the synthesis of organic compounds in the
solution phase.
[0029] For the synthesis of compounds, appropriate starting
materials may be attached to a support. Preferred support materials
include solid polymeric materials, such as polyacrylamide,
polydextran, polyethylene glycol, polystyrene, cellulose, sephadex,
resins, combinations thereof, and the like. Alternate support
materials include glass, acrylic, latex, and ceramics. Synthetic
reactions may be conducted on the support-bound starting materials
to obtain the desired compounds which may then be cleaved from the
support.
[0030] As will be readily apparent to one skilled in the art, the
present invention may be employed in essentially any synthetic
reaction. For details, please see co-pending, commonly assigned
U.S. Provisional Patent Application No. 60/063,134 (Attorney Docket
No. 16925-001900) filed on Oct. 22, 1997, the full disclosure of
which is incorporated herein by reference for all purposes.
[0031] A "combinatorial library" is a collection of compounds in
which the compounds comprising the collection are composed of one
or more subunits or monomeric units (i.e. synthons). The subunits
may be selected from natural or unnatural moieties including amino
acids, nucleotides, sugars, lipids, carbohydrates, dienes,
dienopholes, and the like. The compounds of the combinatorial
library differ in one or more ways with respect to the type(s),
number, order or modification of the subunits comprising the
compounds.
[0032] Combinatorial libraries generated by the methods of the
present invention may be screened for pharmacologically or
diagnostically useful compounds, as well as for desired physical or
chemical properties. It will be clear to one skilled in the art
that such screening may be conducted on a library of compounds
which have been separated from the polyvalent support, or may be
conducted directly on the library of compounds which are still
linked to the polyvalent support.
[0033] Referring now to FIGS. 1A-1B and 2, a preferred embodiment
of the present invention will now be described in detail. FIG. 1A
shows one embodiment of a cassette 100 which may be used with wet
chemistries or solid-state chemistries. The embodiment of cassette
100 shown in FIG. 1A contains 48 reaction vessels RV (FIGS. 3A-3B)
for performing a variety of chemical syntheses. The cassette 100
contains reaction vessels which are particular suited for
performing chemical reactions in an inert environment. Further
details about the cassette 100 and the reaction vessels can be
found in co-pending, commonly assigned U.S. patent application Ser.
No. 09/095,731 (Attorney Docket No. 16925-001710), filed on Jun.
10, 1998, the full disclosure which is incorporated herein by
reference for all purposes.
[0034] In preferred embodiments, each reaction vessel has a cap 110
that includes a handle 112 that extends beyond the boundary of
cassette lid or manifold 120. To provide fluid access into the
reaction vessel, the cap 110 of the reaction vessel is rotated so
that openings in the cap align with openings of 122 on the cassette
lid 120 to define a fluid pathway into the reaction vessel. Thus,
the rotation of the cap 110 seals and unseals of the opening into
the reaction vessel.
[0035] In one embodiment, the present invention provides an
interface head 200 that mates with the cassette lid 120. The
interface head 200 is designed for infusion or injection of
materials into the reaction vessels RV. FIG. 1A shows an embodiment
of interface head 200 that mates with a single row of cassette lid
openings 124 (sometimes referred to as liquid ports) on the
cassette lid 120. Preferably, each cassette lid opening 124 can
provide access to at least one reaction vessel RV. Although FIG. 1A
and 1B shows an interface 200 that connects with an entire row of
openings 124, it should be understood that the interface may be
designed to mate with any number of cassette lid openings 124 and
other configurations. For example, the interface head may be a
square device that connects to four cassette lid openings in
cassette lid 124, two of which are located on row of one cassette
lid while.the other two are located on an adjacent cassette lid.
Preferably, each interface head 200 has at least one pin 210 that
mates with the recess or opening 126 on handle 112 the reaction
vessel cap 110. FIG. 1B shows the interface head 200 coupled to the
cassette 100. The pin 210 typically has a handle 112 to allow for
manual operation. As described in further detail below, the pin 210
may be rotatably moved as indicated by arrow 214 to adjust the
position of handle 112, thus opening and closing the cap 110 over
the reaction vessel.
[0036] As shown in FIG. 2, the cassette 100 is typically mounted on
a heating and agitation unit 250. The interface head 200 is
typically connected to the cassette lids 120 in a sequential manner
as indicated by arrows 251. The cassette 100 is slightably engaged
onto rails of the heating and agitation unit 250 as indicated by
arrows 252. The cassette 100 may be removed from the agitation unit
250 by pulling it in the direction indicated by arrow 253. The
cassette 100 may be aligned as shown in FIG. 2. It should be
understood, however, that the cassette 100 may be designed in other
embodiments to have configurations other than those shown in FIG.
2, such as having cassette lids 120 perpendicular to the
orientation in FIG. 2. The heating and agitation unit 250 typically
has a reciprocating cam mechanism 254 powered by motor 255 that
moves the cassette 100 in the directions indicated by arrows 252.
The unit 250 has a fan 256 that circulates and preferably
recirculates a dry gas about the underside of the cassette 100. The
gases may be either heated or cooled to create the desired
temperature effect. Further details provided in commonly assigned,
copending U.S. patent application Ser. No. 09/176,615 (Attorney
Docket No. 16925-001920) filed on Oct. 21, 1998, the full
disclosure of which is incorporated herein by reference for all
purposes.
[0037] The interface head 200 of FIG. 1A may be connected to the
cassette 100 while the cassette is a stand-alone unit such as on a
workbench, as shown in FIG. 1A, or alternatively when the cassette
100 is mounted on the heating and agitation unit 250 (FIG. 2).
Preferably, the interface head 200 is pressed down onto the
cassette lid 120 to engage the pins 210 with the openings 126 (FIG.
3C). As seen in FIG. 1A, the cassette 100 has a plurality of
openings 130 which facilitate the alignment of the interface head
120 prior to the engagement of pins 210 with openings 126:
preferably, the user visually aligns pins 210 with openings 126
prior to lowering the interface 200 onto the cassette lid 120. For
example, all of the handles 112 may be moved to a far right
position while handles are moved into a corresponding position. The
interface 200 may be used in a serial manner as indicated by arrows
251 of FIG. 2 to provide access to a plurality of cassette lid
openings 124. In one embodiment, such movement is provided by
having a user manually lift and place the interface head 200 onto
the cassette lid 120 through the use of handles 270. Of course, the
interface head may also be designed for robotic manipulation to
automate the chemical synthesis process. The interface head 200 may
be made of a variety of materials such as aluminum, polyphenyl
sulfide, or other thermal and stress resistant material.
[0038] Referring now to FIGS. 3-5, an interface head according to
the present invention will be described in further detail. The
interface head may assume a variety of configurations to fit the
desired function. For example, there are interface heads which
allow for the injection of fluid or other reagents into the
reaction vessels. There are also interface heads which allow for
the extraction of reagents or products from the reaction vessels.
Additionally, there are interface heads which combine the
functionality of both injection and extraction.
[0039] FIG. 3A shows the cross-section of an injection interface
head 200 as it is about to engage a reaction vessel RV mounted
below in cassette lid 120. As shown in FIG. 3A, the interface head
200 has a septa valve 300 that allows devices such as pipets and
syringes to manually deliver reagents to the reaction vessels RV.
When a syringe needle or other piercing device is used, the needle
may pierce through the septum portion 301 of the septa valve. When
a nonpenetrating member is used, the member such as a pipet P is be
inserted through interface head opening 302 through septum opening
304 and into a preferably tapered passageway 306 with an inlet 307
(FIG. 3B). The distal tip of pipet P preferably forms a
circumferential seal with tapered passageway 306. This seal
minimizes the entry of contaminants into the reaction vessel when
the vessel is operating in an inert environment. Alternatively,
positive gas pressure supplied by source 320 may prevent the entry
of airborne contaminants into the interface head 200.
[0040] In the present embodiment (FIG. 3A), septa valve 300 has a
slide 310 which is an elongate member that can move in the manner
indicated by arrow 312. Such movement, typically in the lateral
direction, slides the septum ports or openings 304 to open or close
passageway 306 and passageway 308. Specifically, the slide 310 is
movable between a first position where the septum portion 301 of
the slide 310 seals the inlet of passageway 306 and a second
position where septum ports 304 are in alignment with the inlet of
the passageway 306 and gas and solvent port 302. A distal end 313
having a wedge-shaped profile and handle 314 limit the range of
motion of the septa valve slide 310. The slide 310 is preferably of
sufficient length to control opening and closing of all openings
302 on the interface head 200. It should be understood of course,
that in alternative embodiments, the septum valve does not
necessarily cover all inlets 307 leading into the passageway
306.
[0041] After reagent has been delivered into inlet passageway 308,
the slide 310 is preferably positioned to seal the opening 302.
Typically, the injection head 200 is coupled to a pressurized gas
source and to a gas vent. During operation of the injection head
200, fluid reagents are preferably supplied into inlet passageway
308 through the use of pipet P passing through septum opening 304
or by using a syringe to pierce the septum when septum opening 304
is in a closed position. Pressurized gas from source 320 may then
be introduced through port 322 to blow reagents or wash solution
from passageway 308 into the reaction vessel. Gas from source 320
may also be introduced into the tapered passageway 306 during
injection to establish a positive pressure that prevents air from
flowing into the reaction vessel during injection. FIG. 4 shows
connections 321 for gas sources and vents. Preferably, the gases
used are inert to the chemistries in the reaction vessel and will
not interfere with chemical synthesis. The introduction of such
inert gas is controlled by switch 330. When gas is flowing into the
injection interface head 200, port 332 may allow for the exhaust of
excess gas from the reaction vessel to a gas vent 334 that is
fluidly coupled to the interface head. The septum is preferably
made of a layer of sealing material such as silicone. This sealing
material is typically bonded to a layer of chemically inert and
protective material such as PTFE or Teflon.RTM. on each side so
that the septum is inert to the chemistries used in synthesis but
allows for penetration of a syringed needle through the septum
portion 301. In one embodiment, the septum is 1/8" thick silicone
bonded on both sides with 0.003" thick PTFE. Other known septum
materials and thicknesses may also be used. A Kal-Rez O-ring 340 or
similar elastomeric sealing member may be provided about each
tapered passage 306 to facilitate a seal with slide 310.
[0042] Although the embodiment of FIG. 3A uses a slide 310 to open
and close access to tapered passage 306, it should be understood
that a variety of valving in septum devices may be used to control
access. For example, the head 200 may have a rotatably activated
valve that opens or closes access to into tapered passage 306. Such
valving may be activated individually or coupled together
simultaneous activation. The present invention may also use higher
pressure pipettes or injection devices that can cleanly deliver the
agents into the liquid into the reaction vessel without introducing
contaminant gas or using solvent chase fluids (dilutes reagents) to
deliver the entire amount of reagent into the reaction vessel. It
is particularly desirable to deliver the entire amount of reagent
into the reaction vessel due to the cost of some types of
reagents.
[0043] Referring to FIG. 3A, the interface head 200 has a plurality
of tubular members or interface tubes 402 designed to engage
cavities or passages in the cassette lid 120. As the tubular
members 402 engage passages 420 in the cassette lid 120, a
circumferential seal is formed between the tubular members and the
passages. As seen in FIG. 3B, the passages 420 lead to the first
upper port 422 and second upper port 424 of the reaction vessel RV
when cap 110 is in the open position. It should be understood of
course, that in some alternative embodiments, the passages 420 may
be incorporated into a portion of the cap 110 used with the
reaction vessel RV. To facilitate alignment of the interface head
200 with the cassette 100, a guide pin 400 engages the opening 130
prior to full engagement of the interface head against the lid 120
of the cassette. The guide pin 400 will prevent full engagement of
the interface head against the cassette 100 when the head 200 is
not properly aligned.
[0044] Referring now to FIG. 3B, a cross-section of an interface
head 200 mounted on to a cassette 100 is shown. The interface head
200 has an inlet passageway 308 which allows fluid or other
materials to be delivered towards the reaction vessel RV. As shown
in FIG. 3B, the cap 110 has a first position (as shown in the
reaction vessel on the right) where the inlet passage 308 is
fluidly coupled to a tube 309 leading to the bottom of the reaction
vessel RV. The fluid may be introduced from port 302 or from port
322. The fluid pathway into the reaction vessel RV comprises the
tapered passage 306, the infusion passage 308, and those passages
leading to reaction vessel tube 309.
[0045] As shown in the reaction vessel on the left, the cap 110 may
be moved to a second position where access to the interior of the
reaction vessel RV is sealed. In place of a fluid path leading to
the interior of the reaction vessel, the cap 110 has a groove 307
defines a U-shaped fluid path with the inlet passage 308 and vent
passage 311. Fluid flow through these passages with the cap 110 in
the second position is shown by arrow 308. Hence, when the cap is
in the first position, materials may be delivered or extracted from
the interior of the reaction vessel. When the cap 110 is in the
second position, the U-shaped fluid path allows the passages 302
and 306 to be washed with solvents to create a cleaned fluid path
without residual materials that may effect the next reagent
delivery.
[0046] FIG. 4 shows the slide 310 of the septa valve 300 removed
from the interface head 200. The septa ports 304 on the slide 310
are typically arranged in a linear array, corresponding to the
positions of the openings 302 in the interface head 200. The septum
portion 301 of slide 310 preferably surrounds those areas around
the ports 304. The slide 310 is received in slot 390 in the
interface head 200 and may be reciprocated as indicated by arrow
312 in FIG. 3A.
[0047] FIG. 5 shows the underside of injection manifold 200 and in
further detail. As shown in the figure, alignment pin 400
preferably extends beyond the lower end of the connectors 402. As
shown in FIG. 1A, the alignment pin 400 will fit into recess 130
when the interface head 200 is properly positioned to engage the
cassette lid 120. This alignment will cause pin 400 to contact the
upper surface of cassette lid 120 and prevent meeting of the
interface head 200 with the cassette lid 120.
[0048] As seen in FIG. 5, the handle 212 and pin 210 rotate about
the cylindrical structure 410 supporting the connectors 402. This
provides the proper range motion for pin 210 when it is engaged
with handle 112 of the valve cap 110. As shown in FIG. 3A, when the
interface head 200 is lowered down to the cassette lid 120 and
reaction vessel RV, the connectors will slidably engage receiving
passages 420 in the cassette 100. Interference of approximately
0.003" to 0.006" provide a seal between the connector 402 and the
passage 420. Preferably this seal is a radial seal between the side
walls of the connector 402. The tube may have a diameter between
about 0.080-0.100", preferably about 0.090" diameter. The connector
402 is preferably made of a resilient, chemically inert material
such as Teflon.RTM. or specifically FEP (Fluorinated Ethylene
Propylene). Other fluoropolymers such as PTFE
(Polytetrafluoroethylene), ETFE (Tefzel), and PFA may also be used.
This provides for a reliable seal while maintaining this fluid
pathway inert to the chemistries used in chemical synthesis.
Further details can be found in co-pending, commonly assigned U.S.
patent application Ser. No. 09/095,731 previously incorporated
herein by reference.
[0049] Referring to FIG. 6, preferred embodiments of the connector
402 comprise a smooth extruded tube of FEP. FEP is a material which
cannot be easily reshaped or drilled without causing brittleness or
an unsmooth surface, except in an extrusion process. Accordingly,
the present invention, uses an extruded tube which is inserted into
support 410. The connector 402 is typically press-fit into the
support 410 and is preferably a non-piercing member. An exemplary
embodiment, threading 420 such as that provided by an internally
and externally threaded annular body is used to hold the connector
to the support body 410 during coupling an decoupling with the
cassette 100. Excessive temperature variation such as between
150.degree. C. minus 40.degree. C., of the cassette 110, may cause
the passage 420 to tightly grip the connector 402 when the
interface head is being decoupled. This may cause the connector 402
to be pulled form the support 410. Threads 430 provide additional
support to the connector 402. It should be noted that the inert
pathway is maintained since a proximal end of connector 402 extends
beyond the threaded portion 430 to connect with port 440 in the
support 410.
[0050] Referring now to FIG. 7, an alternative embodiment of the
present invention will now be described. FIG. 7 shows an interface
head 500 for use with a single cassette lid opening 124. The
interface head 500 may be adapted to fit about the distal end of a
pipe head P or an injection syringe (not shown). The head 500 may
be connected to a gas source 502 and a vent 504 and in a manner
similar to the interface head 200 best described in FIG. 3A. The
interface head 500 may also have a valve 506 for sealing the upper
opening 508 of the interface head 500. Such a device may be adapted
for use with a variety of injection devices used to introduce free
agents. The head 500 may also be adapted for extraction
purposes.
[0051] FIGS. 8-10 show alternative designs for fluid delivery
connectors used on the interface head to engage the cassette 100.
FIG. 8 shows a block of inert material such as Teflon.RTM. having 2
lumens 602 and 604. An external annular ring 606 of resilient
Teflon.RTM. material such as FEP may be used to provide a radial
seal with opening 124 while maintaining the chemical inertness of
the device. FIG. 9 shows similar embodiment having a pointed distal
tip which would engage a matching recess (not shown) to receive the
connector 610. As can be seen in FIG. 9, external layer of
resilient inert material 606 is also provided. The further
alternative embodiment shown in FIG. 10, the designs are reversed
where the interface head has passages 420 or female connectors
while the cassette has connectors 402 or male connectors. It should
be understood that a variety of slidable connectors may be used,
preferably providing a reliable seal and inert chemistry. For
example, the device may use O-rings located on the distal tip of
connectors 402 to provide a positive compressive seal with passage
420. Such press or force may be provided by clamps or other locking
mechanisms provided the exterior surface of the interface head.
[0052] Referring to FIGS. 11 and 12, when a head is adapted for
extraction of liquid from the reaction vessel, pressure is provided
into the reaction vessel so as to force fluid out of vent passage
620 and up through opening 622. Preferably, connectors 624 which
may be permanently fixed or removably coupled to opening 302 will
provide an inert pathway from the reaction vessel to the extraction
container. As described earlier, an interface head may be designed
specifically for injection, for extraction, or for both
injection/extraction. When combined, the passage 306 may be
designed to accommodate both the distal tip of a pipet and a
connector 624. For example, the passage 306 may retain its tapered
configuration but have a latch that can secure the connector 624 to
the passageway.
[0053] Referring to FIG. 13, the interface manifold 690 will now be
described. FIG. 13 shows the common injection passage 700 in
manifold 690 which connect the gas injection ports 322 for each
passage leading to a reaction vessel. A common vent passage 702
which connects the gas vent ports 332 for each passage leading from
a reaction vessel. By controlling which reaction vessel cap 110 is
opened (by using interface valve handle 212), the gas from passage
700 may be used to inject reagent into the reaction vessel.
Alternatively, gas in passage 702 may cause liquid to be pushed out
from the reaction vessel in an extraction process. FIGS. 14-18 show
additional cross-sectional detail of the interface manifold
690.
[0054] Referring to FIG. 19, the interface head of the present
invention is preferably used with a single stand-alone thermal
agitation unit. As shown in FIG. 11, a single agitation unit may
contain 1 cassette 100 and have its own control panel. To be
understood however that the interface head may also be used with a
fully automated system such as that described in co-pending,
commonly assigned U.S. Patent Application No. 60/063,134 (Attorney
Docket No. 16925-001900), filed on Oct. 22, 1997, the full
disclosure which is incorporated herein for all purposes.
[0055] Referring now to FIG. 20, an improved interface head capable
of both injection and extraction will be described in further
detail. As seen in FIG. 20, the interface head 800 incorporates the
pins 210 and handle 212 which are used to open and close the valve
cap 110. The interface head 800 also includes the alignment pin 400
which will prevent engagement of the interface head 800 with the
cassette lid 120 if the devices are improperly aligned. As seen in
FIG. 21, the interface head 800 further includes a plurality of
piston valves 802 which can be used to regulate fluid flow from the
reaction vessels. The piston valves 802 may be individually
actuated to selectively drain fluids from the reaction vessels RV.
As seen in FIG. 21, the interface head 800 includes a plurality of
syringe/pipette ports 302 which can be opened or closed by sliding
the septa valve 310 in the directions as indicated by arrows 312.
Materials extracted from the reaction vessels are removed from the
interface head through a plurality of tubes 804 which are
preferably individually coupled to each extraction port of the
interface head. In the preferred embodiment, the interface head 800
allows an operator to manually insert reagents through port 302
into the reaction vessel. The interface head 800 also allows an
operator to simultaneously fill the reaction vessels RV with a
common solvent or chemical. Fluids inside the reaction vessel RV
may also be drained simultaneously or selectively by controlling
the positions of the piston valves 802. The interface head 800
simplifies many of these common wash procedures by using a computer
controller C which can be programmed to regulate the flow of fluids
to and from the reaction vessels through interface head 800.
[0056] Referring now to FIGS. 22-23, a schematic showing a
cross-section of the interface head 800 will be described in
further detail. As seen in FIG. 22, the interface head 800 is
coupled with a reaction vessel RV. The interface head 800 is
coupled to a plurality of pressurized gas and solvent/chemical
sources. This allows a computer controller to regulate the common
wash cycles used with the interface head 800. FIG. 22 shows the
interface head 800 in use to deliver a common wash solvent into the
reaction vessel RV. Solvents from the source 804 are directed into
the interface head 800 along the common infusion passage 806. Fluid
delivered through common passage 806 may be used to simultaneously
fill a plurality of reaction vessels RV. Typically, membrane valve
808 prevents fluid in the common infusion passage 806 from entering
into the infusion passage 810 and initial inlet passage 811
downstream from the common passage. When gas pressure is released
from the pressure/solvent shut-off source 809, the membrane 808 is
relaxed as shown in FIG. 22 and fluid may flow from the common
passage 806 as indicated by arrow 812 into the infusion passage
810.
[0057] In some instances, it is desirable to pulse the shut-off
pressure from source 809 against the membrane valve 808 so that a
more equal amount of solvent will reach each reaction vessel. Fluid
delivered along common passage 806 will tend to flow more easily
into those initial inlet passages 811 closest to the fluid source
of common passage 806. By repeatedly opening and closing the
membrane valve 808 during one filling cycle, fluid will be able to
reach the more distal inlet passages 811. For example, when the
valve is closed, fluid can fill the entire common passage 806 and
pressure may build therein. When the valve 808 is opened, the
initial burst of fluid exiting into passages 811 will be roughly
equivalent for all of the passages. As flow continues, however,
those passages 811 closest to the fluid source of common passage
806 will again start to divert more fluid. The valve 808 is then
closed and the process repeated so that fluid can be delivered to
the more distant passages 811. When the membrane 808 is not pulsed,
more solvent will be introduced into reaction vessels closest to
the source 804.
[0058] Equal distribution of solvents into the reaction vessels may
also be improved by creating back pressure in the reaction vessels
which limits the flow of solvent into reaction vessels which have
filled more quickly and directing the flow towards those reaction
vessels whichever received less solvent and thus created less back
pressure. As seen in FIG. 22, the vent passage 814 is also
controlled in this embodiment by a portion of membrane 808. During
fill cycles, pressurized gas from vent shut-off 816 presses the
membrane 808 against the vent passage 814 preventing fluid from
flowing from the vent passage to the common vent passage 818. As
fluid fills into the reaction vessel RV, the rising amount of
solvent in the reaction vessel will increase pressure in the vent
passage 814. This back pressure is desirable to allow all the
reaction vessels to fill to a substantially even level of solvent.
In some scenarios, the membrane 808 covering infusion passage 806
and common vent passage 818 may be pulsed or opened briefly to
allow an even amount of back pressure to be released from infusion
passages of all the reaction vessels. This is desirable in
situations where back pressure in all the reaction vessels have
reached a level where solvent flow into the vessel has reached a
substantially slowed rate, such as about 0.1 ml/min. Opening and
closing the valve 808 releases the back pressure but allows it to
build up again to regulate the even distribution of fluids into the
reaction vessels. Fluids exiting through the common vent passage is
carried to the vent/drain source 820 attached to the interface head
800. During each fill cycle, a membrane valve 808 covering the
infusion passage 812 may be pulsed at a substantially higher rate
such as between 10 and 20 pulses per fill cycle than the membrane
valve 808 covering the vent passage 814 which may be pulsed only
once or twice per fill cycle.
[0059] As shown in FIG. 3A, diversity reagents or other chemicals
may be manually introduced into the interface head 800 through port
302 as indicated by arrow 822. Chemicals introduced through the
port 302 will flow into the reaction vessel RV through infusion
passage 810. Pressurized gas or solvent may be flowed into the
passage 810 after the diversity reagent or chemicals have been
introduced. The pressurized gas or solvent will ensure that the
diversity reagents which are typically in small quantities, such as
about 5 to 1000 .mu.l, find their way into the reaction vessel.
Since each reaction vessel RV may require a different diversity
reagent, these chemicals are typically introduced manually into
reach reaction vessel. Typically, however, the majority of
processing in the reaction vessel comprises solvent washes and the
like. Hence, automating the common wash procedure substantially
reduces labor on the operator to manually wash each reaction
vessel.
[0060] Referring now to FIG. 23, when processing is complete,
materials in the reaction vessels may be extracted through the
interface head 800. As seen in FIG. 23, pressurized gas from the
source 820 is supplied to common vent passage 818 and then supplied
into vent passage 814. Shut-off pressure from source 816 is removed
to allow the membrane 808 to flex, fluidly coupling the passages
818 and 814. The pressurized gas entering the reaction vessel RV
will force fluid in the reaction vessel to flow in the direction
indicated by arrow 824. The extracted fluid will enter extraction
passage 826 which will lead to the collection manifold 828.
Membrane valve 830 controls flow between the extraction passage 826
and collection manifold passage 832. By releasing the pressure from
the valve shut-off 834, fluid from the reaction vessel RV may flow
into the collection manifold 828. The extraction valve 830 may be
pulsed in a manner similar to the flat valve 808 covering infusion
passage 812 to regulate the flow from the reaction vessel to the
collection manifold 828. The piston valve 802 which is typically
held in the open position, may be closed to selectively vent some
but not all of the reaction vessels coupled to the interface head
800. Placing the valve 802 in the closed position will prevent vent
pressure from extracting fluids from the reaction vessel.
[0061] Referring now to FIGS. 24 and 25, the manifold 834 used in
the interface head 800 will be described in further detail. FIG. 24
shows the front side of the interface manifold 834. The surface 836
on the manifold 834 has a groove 838 which defines a common
infusion passage. The common infusion passage is used to supply
wash solvent to each of the reaction vessels coupled to the
interface head 800. Fluid introduced through port 840 travels the
length of the groove 838 and enters the openings 842 of the inlet
passages as can be seen in FIG. 22. When assembled in the interface
head 800, the membrane 808 will be positioned as indicated by
arrows 844 to substantially cover the surface 836. As described in
respect to FIG. 22, the membrane 808 is used to regulate the common
introduction of wash solvents into the plurality of reaction
vessels. Pressurized gas from source 809 is used to open and close
the membrane valve 808.
[0062] FIG. 25 shows a backside view of the interface manifold 834.
The interface manifold 834 has a backside surface 846. In this
embodiment of the manifold 834, a groove in the surface 846 is used
to define the common vent passage 818. As seen in FIG. 22, the
common vent passage 818 is used to relieve vent pressure from the
reaction vessels RV. Vent pressure exiting the vent passages 814
pass from ports 848 into the common vent passage 818. Fluid exiting
from the vent passages 814 flow in the direction indicated by arrow
850 to the vent port 852. A membrane similar to membrane 808 as
shown in FIG. 24 is positioned over surface 846 to regulate the
flow of fluid between the openings 848 and the common vent passage
818. As discussed in regards to FIG. 22, the opening and closing of
the membrane valve covering openings 848 and the common vent
passage 818 may be regulated by pressurized gas supplied by source
816 or by positioning of the piston 854 of valve 802. The use of
pressurized gas from source 816 provides for the simultaneous
opening and closing of the vent passages 814 while the piston valve
802 is used to selectively open or close the vent passages
individually.
[0063] As shown in FIG. 23, fluid flow through the common vent
passage 818 may be reversed to introduce pressurized gas into the
reaction vessel RV. The pressurized gas is used to extract fluid
from the reaction vessels RV in the direction indicated by arrow
824 towards the collection manifold 828. In this scenario,
pressurized gas flows from the common vent passage 818 into ports
848 towards reaction vessel RV. Liquid in the reaction vessel RV is
forced up the infusion passage 810 as indicated by arrows 824. As
liquid enters the extraction passage 826, liquid will encounter
membrane valve 830 which controls fluid flow between ports 854 and
856. Pressurized gas from source 834 controls the opening and
closing of the membrane valve 830. When pressurized gas is supplied
to the chamber 831 fluid flow is stopped between the port 854 and
port 856. Typically, pressurized gas from source 834 simultaneously
opens or closes all of the ports 854 and 856 on the manifold 834.
Fluid flows from port 854 directly into port 856 without entering a
common extraction passage which may cause cross-contamination of
the materials extracted from each reaction vessel RV.
[0064] Although FIGS. 22 and 23 show a cross-section of the
interface head 800 depicting all passages in the interface head for
ease of illustration, preferred embodiments of the interface head
900 typically has these passages located in different
cross-sectional planes to facilitate manufacturing. Referring to
FIGS. 26-30, a preferred embodiment of the interface head 900 will
be described in further detail. FIG. 26 provides a top-down view of
the interface head 900 showing the valves 802 located on the
backside of the interface head and handles 212 located on a front
side of the interface head to control the position of the cap
valves on the reaction vessels RV. Referring now to FIG. 27 which
shows a cross-section of the interface head 900 of FIG. 26 along
lines 27-27, it can be seen that the infusion passage 810 and
extraction passage 826 are located in the same plane of the
interface head. FIG. 28 taken along lines 28-28 shows that the vent
passage 814 is also located in a different cross-sectional plane.
As shown in FIG. 25, the vent passage 814 is positioned to open on
to the backside of the interface manifold 834 to facilitate the
positioning of the piston valve 802. This differs from the
embodiment shown in the schematic of FIG. 22 where the initial
inlet passage 811 opens on to the same side as the vent passage
814. FIGS. 29 and 30 show that the initial inlet passage 811 and
passage 832 leading to the collection manifold 828 are also located
in separate cross-sectional planes of the interface head. As seen
in FIG. 29, the initial inlet passage 811 is positioned to carry
fluid from the common infusion passage 818 to open at a location
just below the septa valve 310. This allows wash solvent introduced
from the common infusion passage 818 to wash or carry any diversity
reagent just below the septa valve into the infusion passage
810.
[0065] While the invention has been described and illustrated with
reference to certain particular embodiments thereof, those skilled
in the art will appreciate that various adaptations, changes,
modifications, substitutions, deletions, or additions of procedures
and protocols may be made without departing from the spirit and
scope of the invention. For example, more than one interface head
may be used simultaneously with one cassette device. Additionally,
the number of tubular members 402 attached to the interface head
may also be varied, depending on the desired usage of the head.
Expected variations or differences in the results are contemplated
in accordance with the objects and practices of the present
invention. It is intended, therefore, that the invention be defined
by the scope of the claims which follow and that such claims be
interpreted as broadly as is reasonable.
* * * * *