Quantitative diagnostic assay employing signal producing agent bound to support and measuring migration distance of detectable signal

• US 4,973,549 A
• Filed: 06/22/1987
• Issued: 11/27/1990
• Est. Priority Date: 06/22/1987
• Status: Expired due to Term

• Current Assignee: Chemtrak
• Original Assignee: Chemtrak
• Inventors: Khanna, Pyare, Singh, Prithipal
• Primary Examiner(s): Kepplinger, Esther L.
• Assistant Examiner(s): Spiegel, Carol A.
• Application Number:
  US07/064,883
• Time in Patent Office: 1,254 Days
• Field of Search: 435/11, 435/14, 435/25, 435/28, 435/805, 436/518, 436/536, 436/807, 436/810, 436/904, 422/56, 422/59, 422/61, 422/68, 422/70, 422/57
• US Class Current: 435/11
• CPC Class Codes: C12Q 1/00 Measuring or testing processes involving enzymes, nucleic acids or microorganisms measuring or testing apparatus with condition measuring or sensing means, e.g. colony counters, C12M1/34; Compositions therefor; Processes of preparing such compositions
• CPC Class Codes: C12Q 1/26 involving oxidoreductase
• CPC Class Codes: Y10S 435/805 Test papers
• CPC Class Codes: Y10S 436/807 Apparatus included in process claim, e.g. physical support structures
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick
• CPC Class Codes: Y10S 436/904 Oxidation - reduction indicators

Abstract

Methods and kits are provided for detecting analytes, which can be measured directly or indirectly, by production of an enzymatic product. The enzymatic product reacts with a signal producing reagent bound to a bibulous strip. Various devices are employed for producing a reaction, directly or indirectly, with the analyte and then providing for migration of the product through the bibulous strip with reaction with the reagent to produce a detectable signal. The distance from a pre-determined site to the border of the detectable signal is a quantitative measure of the analyte in the sample.

Claims

1. A method for determining total cholesterol present in a blood or serum sample as cholesterol or cholesterol esters, employing a reagent system which reacts with said cholesterol and cholesterol esters to produce hydrogen peroxide which reacts with a chromogen reagent produce a detectable signal, and employing a bibulous support comprising a calibrated measurement zone to which said chromogen reagent is bound, said method comprising:

contacting at an assay mixture receiving site on said support an assay mixture comprising a sample suspected of containing said cholesterol and cholesterol esters in a liquid medium and an enzyme reaction system comprising cholesterol esterase and cholesterol oxidase whereby said sample and said enzyme reaction system react substantially to completion to produce said hydrogen peroxide;

dipping one end of said bibulous support distant from said measurement zone into a solution comprising horseradish peroxidase, whereby said solution migrates through said assay mixture receiving site into said measurement zone whereby said hydrogen peroxide reacts with said chromogen to produce a detectable signal; and

measuring in said calibrated measurement zone the furthest distance from said receiving site of the detectable signal as a measure of the amount of total cholesterol in said sample.

2. A method according to claim 1 wherein said chromogen is 4-chloro-1-naphthol.

3. A method according to claim 2 wherein said assay mixture receiving site is proximal to said one end of said bibulous support.