Apparatus and process for arraying beads

• US 5,935,859 A
• Filed: 07/29/1998
• Issued: 08/10/1999
• Est. Priority Date: 01/17/1997
• Status: Expired due to Fees

• Current Assignee: Smithkline Beecham Corporation (GSK plc)
• Original Assignee: Smithkline Beecham Corporation (GSK plc)
• Inventors: Simolike, Gerald C., Leber, Jack Dale, Gleason, John Gerald, Elliott, John Duncan
• Primary Examiner(s): Le, Long V.
• Application Number:
  US09/124,802
• Time in Patent Office: 377 Days
• Field of Search: 422/63, 422/65, 422/67, 422/81, 422/100, 422/104, 636/43, 636/47, 636/69, 636/54, 636/174, 636/180
• US Class Current: 506/33
• CPC Class Codes: B01F 33/405 in receptacles having guiding conduits therein, e.g. for feeding the gas to the bottom of the receptacle
• CPC Class Codes: B01J 19/0046 Sequential or parallel reactions, e.g. for the synthesis of polypeptides or polynucleotides; Apparatus and devices for combinatorial chemistry or for making molecular arrays synthesis methods per se C40B50/00
• CPC Class Codes: B01J 2219/00315 Microtiter plates
• CPC Class Codes: B01J 2219/00459 Beads
• CPC Class Codes: B01J 2219/00468 by manipulation of individual beads
• CPC Class Codes: B01J 2219/005 Beads
• CPC Class Codes: B01J 2219/00659 Two-dimensional arrays
• CPC Class Codes: C40B 60/14 for creating libraries
• CPC Class Codes: G01N 2035/00574 Means for distributing beads
• CPC Class Codes: G01N 35/0099 comprising robots or similar manipulators robots per se B25J
• CPC Class Codes: G01N 35/028 having reaction cells in the form of microtitration plates
• CPC Class Codes: Y10T 436/114998 with treatment or replacement of aspirator element [e.g., cleaning, etc.]
• CPC Class Codes: Y10T 436/119163 with aspirator of claimed structure
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

A mixture of beads from a combinatorial library is held in suspension either by inducing circulating flow of a liquid in a tapered vessel by rising air bubbles or by floating the beads at the interface between two immiscible liquids. Beads are selected individually from the suspension by drawing liquid into the tip of a needle having a circular opening smaller than the diameter of a bead. After a bead is captured on the tip of a needle, excess beads are jarred loose or washed away by flow of a solvent through a sheath surrounding the needle, and the needle is moved by a robotic manipulator to a well into which the bead is released.

Claims

1. A process for arraying beads which comprises:

establishing, in a vessel, a suspension comprising a mixture of beads in a liquid, and preventing the beads from settling in said vessel;

introducing into said suspension a hollow movable element having an internal passage with an opening at an end thereof, the opening being of a size smaller than any one of the beads, being shaped so that it can be substantially closed off by a bead, and being positioned, when the hollow movable element is introduced into the vessel, at a location within the vessel such that it can be approached and closed off by any one of the beads of said mixture;

drawing liquid from said vessel into said internal passage through said opening and thereby inducing approaching movement of at least one bead toward the opening, until one bead closes off the opening;

when said one bead closes off the opening, establishing a pressure differential such that the external pressure exerted on the bead closing off the opening is greater than the pressure within the passage, thereby holding the bead in engagement with the opening;

withdrawing the movable element from the vessel with the bead in engagement with the opening; and

depositing the bead at a location remote from the vessel by releasing the bead from the opening.

2. The process according to claim 1 in which the beads are spherical and the opening is circular.

3. The process according to claim 1 in which, after said one bead closes off the opening at the end of the internal passage of the hollow movable element, the hollow movable element is jarred to dislodge any beads adhering to it other than the one bead closing off the opening.

4. The process according to claim 1 in which, after said one bead closes off the opening at the end of the internal passage of the hollow movable element, a fluid is caused to flow over at least a part of the hollow movable element to dislodge any beads adhering to it other than the one bead closing off the opening.

5. The process according to claim 1 in which the hollow movable element is a needle.

7. The process according to claim 1 in which the beads of the mixture are held in suspension in the liquid by introducing a flow of gas into the vessel to produce gas bubbles therein.

8. The process according to claim 1 in which at least a portion of the interior of the vessel extending upwardly from the bottom thereof has a continuously increasing horizontal cross-section in the upward direction, and in which the beads of the mixture are held in suspension in the liquid by introducing a flow of gas into the liquid in the vessel at the bottom thereof to produce rising gas bubbles in the liquid.

10. The process according to claim 1 in which the step of drawing liquid is preceded by applying pressure to gas in the internal passage of the hollow movable element, and sensing flow of gas through said opening in response to the applied pressure, to detect clogging of the internal passage.

6. A process for arraying beads which comprises:

drawing liquid, from a vessel containing a mixture of beads suspended in a liquid, into an internal passage of a hollow movable element through an opening at an end of the internal passage, the opening being of a size smaller than any one of the beads and being shaped so that it can be substantially closed off by a bead;

when a bead closes off the opening, establishing a pressure differential such that the external pressure exerted on the bead closing off the opening is greater than the pressure within the passage, thereby holding the bead in engagement with the opening;

withdrawing the movable element from the vessel with the bead in engagement with the opening; and

depositing the bead at a location remote from the vessel by releasing the bead from the opening;

in which the hollow movable element comprises a hollow needle extending along an axis and a sheath coaxial with and surrounding the needle, and spaced therefrom to provide an annular passage surrounding the needle, in which the internal passage is a passage within the needle, and in which, after the bead closes off the opening at the end of the internal passage, a fluid is caused to flow through the annular passage to dislodge any beads adhering to the hollow movable element other than the bead closing off the opening.

9. A process for arraying beads which comprises:

drawing liquid, from a vessel containing a mixture of beads suspended in a liquid, into an internal passage of a hollow movable element through an opening at an end of the internal passage, the opening being of a size smaller than any one of the beads and being shaped so that it can be substantially closed off by a bead;

when a bead closes off the opening, establishing a pressure differential such that the external pressure exerted on the bead closing off the opening is greater than the pressure within the passage, thereby holding the bead in engagement with the opening;

withdrawing the movable element from the vessel with the bead in engagement with the opening; and

depositing the bead at a location remote from the vessel by releasing the bead from the opening

in which the liquid in which the beads are suspended comprises two immiscible liquid components, one component floating on the other, in which the density of the beads is higher than the density of the one component and lower than the density of the other component, whereby the beads are suspended at the interface of the two components, and in which the drawing of liquid is carried out as the opening at the end of the internal passage of the hollow movable element is moved through the interface.

11. An apparatus for arraying beads which comprises:

a vessel containing a mixture of beads suspended in a liquid;

means for preventing the beads from settling out of the suspension in said vessel;

a hollow movable element having an internal passage and an opening at an end of the internal passage, the opening being circular in shape so that it can be substantially closed off by a spherical bead;

means for introducing the hollow movable element into the suspension and positioning the opening within the suspension at a location such that it can be approached and closed off by any one of the beads of the mixture;

means for drawing liquid from the vessel into the internal passage of the hollow movable element through the opening, for establishing a pressure differential such that the external pressure exerted on the bead closing off the opening is greater than the pressure within the passage, thereby holding the bead in engagement with the opening, and for depositing the bead at a location remote from the vessel by releasing the bead from the opening; and

means for withdrawing the movable element from the vessel with the bead in engagement with the opening and for moving the movable element to said remote location.

12. A process for arraying beads which comprises:

establishing, in a vessel, a suspension comprising a mixture of beads in a liquid, and preventing the beads from settling in said vessel by introducing a flow of gas into the vessel to produce gas bubbles therein or by maintaining, in the vessel, two immiscible liquid components, one component floating on the other, in which the density of the beads is higher than the density of the one component and lower than the density of the other component, whereby the beads are suspended at the interface of the two components;

drawing liquid, from said vessel into an internal passage of a hollow movable element through an opening at an end of the internal passage, the opening being of a size smaller than any one of the beads and being shaped so that it can be substantially closed off by a bead;

when a bead closes off the opening, establishing a pressure differential such that the external pressure exerted on the bead closing off the opening is greater than the pressure within the passage, thereby holding the bead in engagement with the opening;

withdrawing the movable element from the vessel with the bead in engagement with the opening; and

depositing the bead at a location remote from the vessel by releasing the bead from the opening.

13. A process according to claim 12 in which the step of preventing the beads from settling in said vessel is carried out by introducing a flow of gas into the vessel to produce gas bubbles therein.

14. A process according to claim 12 in which the step of preventing the beads from settling in said vessel is carried out by maintaining, in the vessel, two immiscible liquid components, one component floating on the other, in which the density of the beads is higher than the density of the one component and lower than the density of the other component, whereby the beads are suspended at the interface of the two components.

15. An apparatus for arraying beads which comprises:

a vessel containing a mixture of beads suspended in a liquid;

means for preventing the beads from settling out of the suspension in said vessel said preventing means comprising means for introducing a flow of gas into the vessel to produce gas bubbles therein or means for maintaining, in the vessel, two immiscible liquid components, one component floating on the other, in which the density of the beads is higher than the density of the one component and lower than the density of the other component, whereby the beads are suspended at the interface of the two components;

a hollow movable element having an internal passage and an opening at an end of the internal passage, the opening being circular in shape so that it can be substantially closed off by a spherical bead;

means for drawing liquid from the vessel into the internal passage of the hollow movable element through the opening, for establishing a pressure differential such that the external pressure exerted on the bead closing off the opening is greater than the pressure within the passage, thereby holding the bead in engagement with the opening, and for depositing the bead at a location remote from the vessel by releasing the bead from the opening; and

means for withdrawing the movable element from the vessel with the bead in engagement with the opening and for moving the movable element to said remote location.

16. An apparatus according to claim 15 in which the means for preventing the beads from settling out of the suspension comprises means for introducing a flow of gas into the vessel to produce gas bubbles therein.

17. An apparatus according to claim 15 in which the means for preventing the beads from settling out of the suspension comprises means for maintaining, in the vessel, two immiscible liquid components, one component floating on the other, in which the density of the beads is higher than the density of the one component and lower than the density of the other component, whereby the beads are suspended at the interface of the two components.