Capillary array and related methods

• US 6,610,499 B1
• Filed: 08/31/2000
• Issued: 08/26/2003
• Est. Priority Date: 08/31/2000
• Status: Expired due to Term

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Gray, Joe W., Fulwyler, Mack J.
• Primary Examiner(s): Le, Long V.
• Assistant Examiner(s): Davis, Deborah A
• Application Number:
  US09/652,873
• Time in Patent Office: 1,090 Days
• Field of Search: 435/7.1, 435/6, 436/52, 436/53, 422/81, 422/82, 216/33, 204/604
• US Class Current: 435/7.1
• 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 2219/00479 Means for mixing reactants or products in the reaction vessels
• CPC Class Codes: B01J 2219/00511 Walls of reactor vessels
• CPC Class Codes: B01J 2219/0052 in the shape of elongated tubes
• CPC Class Codes: B01J 2219/00605 the compounds being directly bound or immobilised to solid supports
• CPC Class Codes: B01J 2219/0061 The surface being organic
• CPC Class Codes: B01J 2219/00612 the surface being inorganic
• CPC Class Codes: B01J 2219/00621 by physical means, e.g. trenches, raised areas
• CPC Class Codes: B01J 2219/00626 Covalent
• CPC Class Codes: B01J 2219/00628 Ionic
• CPC Class Codes: B01J 2219/0063 Other, e.g. van der Waals forces, hydrogen bonding
• CPC Class Codes: B01J 2219/00637 by coating it with another layer
• CPC Class Codes: B01J 2219/00641 the porous medium being continuous, e.g. porous oxide substrates
• CPC Class Codes: B01J 2219/00657 One-dimensional arrays
• CPC Class Codes: B01J 2219/00722 Nucleotides
• CPC Class Codes: B01L 2200/0673 Handling of plugs of fluid surrounded by immiscible fluid
• CPC Class Codes: B01L 2300/0636 Integrated biosensor, microarrays
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0838 Capillaries
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0415 : electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0421 : electrophoretic flow
• CPC Class Codes: B01L 2400/0487 : fluid pressure, pneumatics
• CPC Class Codes: B01L 3/502784 : specially adapted for droplet or plug flow, e.g. digital microfluidics automatic analysis using a stream of discrete samples in a tube system G01N35/08
• CPC Class Codes: G01N 33/558 : using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: Y10S 436/807 : Apparatus included in process claim, e.g. physical support structures
• CPC Class Codes: Y10T 436/117497 : with a continuously flowing sample or carrier stream

Abstract

The invention provides methods and devices for detecting the presence of one or more target analytes in a sample employing a channel having affixed therein one or more binding partners for each target analyte. Assays are carried out by transporting the sample through the channel to each successive binding partner so that target analyte present in said sample binds to the corresponding binding partner. The sample is then transported beyond the binding partner(s), followed by detection of any target analyte bound to each binding partner. In one embodiment, binding efficiency is increased by the use of segmented transport, wherein a first bolus or bubble of a fluid that is immiscible with the sample precedes the sample during transport and a second bolus or bubble of a fluid that is immiscible with the sample follows the sample. Many configurations are possible for the device of the invention. A preferred device includes: a substrate with a channel formed in its surface, and a cover element that overlies and seals the channel. Binding partner(s) are affixed to the surface of the cover element facing the channel lumen.

Claims

1. A method of detecting the presence of a first target analyte in a sample, said method comprising:

(a) providing a channel formed in a surface of a substrate, and a cover element overlying and sealing said channel, said cover element having a first surface facing the channel lumen, wherein a first binding partner for said first target analyte is affixed to said first surface of said cover element;

(b) transporting said sample through said channel to said first binding partner so that first target analyte present in said sample binds to said first binding partner, wherein a first bolus or bubble of a fluid that is immiscible with said sample precedes said sample during transport and a second bolus or bubble of a fluid that is immiscible with said sample follows said sample during transport;

(c) transporting said sample beyond said first binding partner; and

(d) detecting the presence of any first target analyte bound to said first binding partner, wherein said cover element is unsealed from said channel to allow said detection.

2. The method of claim 1, wherein said channel is molded in a polymeric material.

3. The method of claim 2, wherein said polymeric material is a polydimethylsiloxane.

4. The method of claim 1, wherein said channel has a hydrophobic lumenal surface.

5. The method of claim 1, wherein said channel has a cross-sectional diameter of about 100 μ

m or less.

6. The method of claim 1, wherein said cover element is removably attached to said substrate.

7. The method of claim 1, wherein said first surface of said cover element is hydrophilic.

8. The method of claim 1, additionally comprising detecting the presence of a second target analyte in a sample, wherein

said channel has affixed therein, and/or said cover element has affixed thereon, a second binding partner for said second target analyte, wherein said second binding partner is affixed at a location distinct from that of said first binding partner;

said sample is additionally transported through said channel to said second binding partner under conditions wherein second target analyte present in said sample binds to said second binding partner, and wherein said first bolus or bubble precedes said sample during transport to said second binding partner and said second bolus or bubble follows said sample during transport to said second binding partner;

said sample is transported beyond said first and second binding partners; and

the presence of any second target analyte bound to said second binding partner is detected.

9. The method of claim 8, wherein said channel and/or cover element comprises at least about 100 different binding partners affixed at distinct locations.

10. The method of claim 1, wherein said immiscible fluids are gas bubbles.

11. The method of claim 10, wherein a film of fluid containing said first target analyte forms between a gas bubble and a lumenal surface of said channel, said film being about 1 μ

m thick or less.

12. The method of claim 7, wherein said immiscible fluids are gas bubbles and a film of fluid containing said first target analyte forms between a gas bubble and said first surface of said cover element, said film being about 1 μ

m thick or less.

13. The method of claim 1, wherein said sample is divided into at least two segments, said segments being separated by a bolus or bubble of a fluid that is immiscible with said sample.

14. The method of claim 1, wherein a buffer solution follows said second bolus or bubble of immiscible fluid.

15. The method of claim 14 wherein said buffer solution is divided into at least two segments, said segments being separated by a bolus or bubble of a fluid that is immiscible with said buffer solution.

16. The method of claim 1, wherein said sample is transported through said channel at a velocity of at least about 1 mm/second.

17. The method of claim 1, wherein fluid is transported in response to a pressure difference.

18. The method of claim 1, wherein said fluid is transported by electrophoretic force.

19. The method of claim 1, wherein said binding partner is selected from the group consisting of an antibody, a binding protein, and a nucleic acid.

20. The method of claim 1, wherein said first target analyte is labeled with a label that produces a signal having an intensity.

21. The method of claim 20, wherein said first target analyte is labeled with a light-absorbing label.

22. The method of claim 20, wherein:

target analytes derived from at least two different sources are present in said sample or are transported through said channel in a plurality of separate samples, wherein target analytes from each source are labeled with a different label;

said channel and/or cover element comprises a plurality of different binding partners affixed at distinct locations;

said detecting comprises detecting the signals from labeled target analytes bound to each different binding partner; and

said method additionally comprises comparing the intensities of any signal produced by each different label at each different binding partner location.

23. The method of claim 19, wherein said binding partner comprises an antibody.

24. The method of claim 19, wherein said binding partner comprises a binding protein.

25. The method of claim 19, wherein said binding partner comprises a nucleic acid.