Method and kit for detecting an analyte

• US 6,271,044 B1
• Filed: 05/06/1998
• Issued: 08/07/2001
• Est. Priority Date: 05/06/1998
• Status: Expired due to Fees

• Current Assignee: University of Pittsburgh of The Commonwealth System of Higher Education
• Original Assignee: University of Pittsburgh of The Commonwealth System of Higher Education
• Inventors: Ballerstadt, Ralph, Schultz, Jerome S.
• Primary Examiner(s): Le, Long V.
• Assistant Examiner(s): Do, Pensee T.
• Application Number:
  US09/073,784
• Time in Patent Office: 1,189 Days
• Field of Search: 436/501, 436/514, 436/518, 436/530, 436/533, 436/535, 436/536, 436/541, 436/827, 436/808, 436/179, 436/529, 435/2, 435/7.1, 435/4, 435/5, 435/6
• US Class Current: 436/518
• CPC Class Codes: G01N 33/53 Immunoassay; Biospecific binding assay; Materials therefor
• CPC Class Codes: G01N 33/536 with immune complex formed in liquid phase
• CPC Class Codes: Y10S 436/808 Automated or kit
• CPC Class Codes: Y10S 436/827 Lectins
• CPC Class Codes: Y10T 436/25625 Dilution

Abstract

The present invention provides a viscometric method of detecting the presence or absence of an analyte in a solution. The method utilizes a dispersion of a conjugate and a receptor. The conjugate functions as an analog of the analyte, and the receptor can interact with both the analyte and the conjugate to change the viscosity of the dispersion. The test solution is introduced into an aliquot of the dispersion. Equivalent spots of the dispersion and the aliquot containing the analyte within the dispersion are then placed on a substrate such that the spots can spread upon the substrate. The presence of analyte in the test solution is detected by noting a change in the viscosity of the dispersion through a comparison of the spots. To facilitate the method, the invention provides a test kit comprising a conjugate comprising an analog of the analyte, a receptor binding the analog and the analyte, and a substrate upon which spots of liquid can spread.

Claims

1. A method of detecting an analyte in a test solution, said method comprising:

(a) providing a liquid composition of a conjugate and a receptor, wherein said conjugate comprises an analog of said analyte, and said receptor interacts with said analyte and said analog,

(b) introducing said test solution into an aliquot of said liquid composition to create a mixture of said liquid composition and said test solution and to leave a volume of said liquid composition unmixed with said test solution,

(c) placing substantially equivalent volumes of said liquid composition and said mixture separately on a substrate such that said volumes spread upon said substrate to form spots, each having an area, and

(d) comparing the relative areas of said spots to provide an indication of the presence or absence of said analyte in said test solution.

2. The method of claim 1 employed for measuring the concentration of said analyte in said test solution, further comprising the steps of:

(e) introducing a known quantity of said analyte into a second aliquot of said liquid composition to create a second mixture,

(f) placing substantially equivalent volumes of said liquid composition and said mixtures on said substrate to form spots, each having an area, and

(g) comparing the relative areas of all spots to provide an indication of the concentration of said analyte in said test solution.

3. The method of claim 2, further comprising:

(e) introducing multiple known quantities of said analyte into aliquots of said liquid composition to create serial dilution mixtures,

(f) placing substantially equivalent volumes of said liquid composition and said mixtures on said substrate to form spots, each having an area, and

(g) comparing the relative areas of all spots to provide an indication of the concentration of said analyte in said test solution.

4. The method of claim 1, wherein said conjugate is dextran.

5. The method of claim 4, wherein said dextran has a molecular weight of about 2000 kDa.

6. The method of claim 1, wherein said receptor is a lectin.

7. The method of claim 6, wherein said lectin is concanavalin A.

8. The method of claim 1, wherein said analyte is selected from the group consisting of glucose and mannose.

9. The method of claim 8, wherein said solution is a blood product.

10. The method of claim 1, wherein said receptor is an antibody.