Devices for performing ion-capture binding assays

• US 5,670,381 A
• Filed: 05/08/1995
• Issued: 09/23/1997
• Est. Priority Date: 01/29/1988
• Status: Expired due to Fees

• Current Assignee: Abbott Laboratories
• Original Assignee: Abbott Laboratories
• Inventors: Markese, James J., Stroupe, Stephen D., Jou, Yi-Her
• Primary Examiner(s): Spiegel, Carol A.
• Application Number:
  US08/436,950
• Time in Patent Office: 869 Days
• Field of Search: 435/7.92-7.95, 435/970, 435/971, 435/6, 435/7.1, 435/7.9, 435/805, 435/810, 436/518, 436/529, 436/536, 436/538, 436/540, 436/541, 436/808, 436/810, 436/824, 436/177, 422/56, 422/59, 422/101, 422/102
• US Class Current: 436/518
• CPC Class Codes: G01N 33/538 by sorbent column, particles or resin strip , i.e. sorbent materials
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 33/54388 based on lateral flow
• CPC Class Codes: G01N 33/54391 based on vertical flow
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: G01N 33/57473 involving carcinoembryonic antigen, i.e. CEA
• CPC Class Codes: Y10S 435/97 Test strip or test slide
• CPC Class Codes: Y10S 435/971 Capture of complex after antigen-antibody reaction
• CPC Class Codes: Y10S 436/808 Automated or kit
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick

Abstract

This invention presents novel assay devices employing capture reagents, involving a specific binding member attached to a charged substance, and porous material containing a capture or reaction zone that is oppositely charged with respect to the charged substance included in the capture reagent. In one embodiment, a test sample suspected of containing the analyte of interest is contacted with the capture reagent to form a charged capture reagent/analyte complex. The complex is then contacted to the oppositely charged capture or reaction zone to attract, attach, and immobilize the capture reagent/analyte complex. With an appropriate indicator reagent, both sandwich and competitive assays can be performed.

Claims

1. A test device for determining the presence or amount of an analyte in a test sample, comprising:

at least three zones in a porous material;

a) a first reagent zone containing a diffusive indicator reagent comprising a first specific binding member bound to a detectable label;

b) a second reagent zone containing a diffusive capture reagent comprising a second specific binding member conjugated to a polymeric ion having a predetermined charge; and

c) a reaction zone having a pre-determined charge opposite to said polymeric ion charge, whereby said capture reagent and complexes comprising said capture reagent are coupled to the porous material by the ionic attraction of the oppositely charged polymeric ion and porous material;

wherein said first and second specific binding members are selected from binding members capable of forming a complex with the analyte in a sandwich assay, a competitive assay or an indirect assay, and thereby forming a detectable complex in proportion to the presence or amount of the analyte in the test sample, and

wherein said zones may overlap with the proviso that said capture reagent is spatially separated from said reaction zone such that the test sample contacts said capture reagent before contacting said reaction zone.

2. The device according to claim 1, wherein said porous material is a porous strip through which the test sample and said diffusive reagents are transported by capillary action.

3. The device according to claim 2, wherein said porous strip comprises a test sample application pad and an elongated portion of porous material in fluid flow contact with said application pad, said elongated portion containing said reaction zone.

4. The device according to claim 3, wherein said test sample application pad contains said indicator reagent.

5. The device according to claim 4, wherein said test sample application pad contains said capture reagent.

6. The device according to claim 3, wherein said test sample application pad contains said indicator reagent and said elongated portion contains said capture reagent.

7. The device according to claim 3, wherein said test sample application pad contains said capture reagent and said elongated portion contains said indicator reagent.

8. The device according to claim 1, further comprising at least one signal producing component immobilized in said reaction zone, wherein said signal producing component reacts with the detectable label to produce a signal in proportion to the presence or amount of the analyte in the test sample.

9. The device according to claim 1, further comprising an end of assay indicator zone, wherein said zone contains a reagent capable of reacting with a member selected from the group consisting of said indicator reagent, a wicking solution, a signal producing component and the test sample to produce a visual signal to indicate that the test sample has completed migration through the test device.

10. The device according to claim 1, wherein said test device further comprises an absorbent means in fluid flow contact with said porous material, wherein said absorbent means serves to increase the amount of test sample which can be contacted to said device and transported through said reaction zone.

11. The device according to claim 1, wherein said reaction zone comprises a detectable design to indicate a positive assay result.

12. The device according to claim 1, further comprising an ancillary binding member capable of binding to the analyte and either said indicator reagent or said capture reagent in the indirect assay.

13. A test kit for determining the presence or amount of an analyte in a test sample, comprising:

a) a vessel containing an indicator reagent comprising a first specific binding member bound to a detectable label, and

b) a test device comprising at least two zones in a porous material;

i) a reagent zone containing a diffusive capture reagent comprising a second specific binding member conjugated to a polymeric ion having a predetermined charge; and

ii) a reaction zone having a pre-determined charge opposite to said polymeric ion charge, whereby said capture reagent and complexes comprising said capture reagent are coupled to the porous material by the ionic attraction of the oppositely charged polymeric ion and porous material;

wherein said first and second specific binding members are selected from binding members capable of forming a complex with the analyte in a sandwich assay, a competitive assay or an indirect assay, and thereby forming a detectable complex in proportion to the presence or amount of the analyte in the test sample, and

wherein said capture reagent is spatially separated from said reaction zone such that the test sample contacts said capture reagent before contacting said reaction zone.

14. The kit according to claim 13, further comprising at least one signal producing component immobilized in said reaction zone, wherein said signal producing component reacts with the detectable label to produce a signal in proportion to the presence or amount of the analyte in the test sample.

15. The kit according to claim 13, further comprising an end of assay indicator zone, wherein said zone contains a reagent capable of reacting with a member selected from the group consisting of said indicator reagent, a wicking solution, a signal producing component and the test sample to produce a visual signal to indicate that the test sample has completed migration through the test device.

16. The according to claim 13, wherein said test device further comprises an absorbent means in fluid flow contact with said porous material, wherein said absorbent means serves to increase the amount of test sample which can be contacted to said device and transported through said reaction zone.

17. The kit according to claim 13, wherein said reaction zone further comprises a detectable design to indicate a positive assay result, said detectable design being selected from the group consisting of numerals, letters, dots, symbols and patterns which display a detectable signal upon completion of the assay in proportion to the presence or amount of the analyte in the test sample.

18. A test kit for determining the presence or amount of an analyte in a test sample, comprising:

a) a vessel containing a capture reagent comprising a first specific binding member conjugated to a polymeric ion having a pre-determined charge, and

b) a test device comprising at least two zones in a porous material;

i) a reagent zone containing a diffusive indicator reagent comprising a second specific binding member bound to a detectable label; and

ii) a reaction zone having a pre-determined charge opposite to said polymeric ion charge, whereby said capture reagent and complexes comprising said capture reagent are coupled to the porous material by the ionic attraction of the oppositely charged polymeric ion and porous material;

wherein said zones may overlap and wherein said first and second specific binding members are selected from binding members capable of forming a complex with the analyte in a sandwich assay, a competitive assay or an indirect assay, and thereby forming a detectable complex in proportion to the presence or amount of the analyte in the test sample.

19. The kit according to claim 18, further comprising at least one signal producing component immobilized in said reaction zone, wherein said signal producing component reacts with the detectable label to produce a signal in proportion to the presence or amount of the analyte in the test sample.

20. The kit according to claim 18, further comprising an end of assay indicator zone, wherein said zone contains a reagent capable of reacting with a member selected from the group consisting of said indicator reagent, a wicking solution, a signal producing component and the test sample to produce a visual signal to indicate that the test sample has completed migration through the test device.

21. The kit according to claim 18, wherein said test device further comprises an absorbent means in fluid flow contact with said reaction zone, wherein said absorbent means serves to increase the amount of test sample which can be contacted to said device and transported through said reaction zone.

22. The kit according to claim 18, wherein said reaction zone further comprises a detectable design to indicate a positive assay result, said detectable design being selected from the group consisting of numerals, letters, dots, symbols and patterns which display a detectable signal upon completion of the assay in proportion to the presence or amount of the analyte in the test sample.

23. A device for separating an analyte of interest from a sample, comprising:

a) a diffusive capture reagent comprising a specific binding member conjugated to a polymeric ion having a pre-determined charge, wherein said capture reagent is capable of directly or indirectly forming a complex with the analyte, and

b) a reaction zone having a pro-determined charge opposite to said polymeric ion charge, whereby said capture reagent and complexes comprising said capture reagent are immobilized by the ionic attraction of the oppositely charge polymeric ion and reaction zone,

wherein said capture reagent is located upstream of said reaction zone and further wherein the sample is contacted to said capture reagent and said reaction zone wherein nonimmobilized sample is removed from said reaction zone.