Polyelectrolytic internal calibration system of a flow-through assay

• US 7,651,841 B2
• Filed: 04/25/2002
• Issued: 01/26/2010
• Est. Priority Date: 12/24/2001
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Sayre, Curt, Wei, Ning, Song, Xuedong
• Primary Examiner(s): Shibuya; Mark L
• Assistant Examiner(s): DIRAMIO, JACQUELINE A
• Application Number:
  US10/132,421
• Publication Number:
  US 20030124739A1
• Time in Patent Office: 2,833 Days
• Field of Search: 435/6, 435/287.2, 435/7.1, 435/287.1, 435/7.92, 435/17, 435/607.4, 436/518, 436/169, 436/501, 436/533, 436/534, 422/56, 422/57
• US Class Current: 435/7.1
• CPC Class Codes: G01N 33/54386 Analytical elements
• CPC Class Codes: G01N 33/54388 based on lateral flow
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387

Abstract

A flow-through assay for detecting the quantity of an analyte residing in a test sample is provided. The flow-through assay contains a porous membrane that is in fluid communication with probe conjugates that contain a specific binding member and a detectable probe. The porous membrane also defines a detection zone and a calibration zone. The calibration zone contains a polyelectrolyte substantially non-diffusively immobilized on the porous membrane. The polyelectrolyte is capable of generating a detectable calibration signal that can be readily compared (visually, quantitatively, and the like) to a detection signal to determine the amount of analyte in the test sample.

Claims

1. A flow-through assay device for detecting an analyte within a test sample, the flow-through assay device comprising a porous membrane in fluid communication with detectable probes conjugated with a specific binding member, the conjugated probes having a net charge prior to the application of a test sample to the device, the porous membrane defining:

a detection zone that contains a capture reagent configured to bind with the conjugated probes or complexes thereof to generate a detection signal; and

a calibration zone positioned downstream from the detection zone, wherein a polyelectrolyte is substantially non-diffusively immobilized on the porous membrane within the calibration zone, the polyelectrolyte having a net charge opposite to that of the conjugated probes, the polyelectrolyte being configured to bind with the conjugated probes to generate a calibration signal.

2. The flow-through assay device of claim 1, wherein the polyelectrolyte has a net positive charge.

3. The flow-through assay device of claim 1, wherein the calibration zone contains at least two distinct regions having a different concentration of the polyelectrolyte.

4. The flow-through assay device of claim 1, wherein the polyelectrolyte is ionically bonded to a functional group present on the surface of the porous membrane.

5. The flow-through assay device of claim 1, wherein the polyelectrolyte is covalently bonded to a functional group present on the surface of the porous membrane.

6. The flow-through assay device of claim 5, wherein the polyelectrolyte is crosslinked to the functional group.

7. The flow-through assay device of claim 1, wherein the detectable probes are selected from the group consisting of chromogens, catalysts, fluorescent compounds, chemiluminescent compounds, radioactive labels, direct visual labels, liposomes, and combinations thereof.

8. The flow-through assay device of claim 1, wherein the detectable probes comprise latex microparticles.

9. The flow-through assay device of claim 1, wherein the specific binding member is selected from the group consisting of antigens, haptens, antibodies, and complexes thereof.

10. The flow-through assay device of claim 1, wherein the capture reagent is selected from the group consisting of antigens, haptens, antibodies, and complexes thereof.

11. The flow-through assay device of claim 1, wherein the capture reagent is configured to bind with complexes formed between the conjugated probes and the analyte.

12. The flow-through assay device of claim 1, wherein the capture reagent is configured to bind with the specific binding member.

13. The flow-through assay device of claim 1, wherein the capture reagent is substantially non-diffusively immobilized on the porous membrane.

14. The flow-through assay device of claim 1, wherein the amount of the analyte within the test sample is quantitatively or semi-quantitatively determined by comparing the detection signal to the calibration signal.

15. The flow-through assay device of claim 1, wherein the calibration zone is generally free of biological capture reagents.