Patent EP0125118A2 successfully refreshed from Google Patents.
EP0125118A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Colorimetric immunoassay on solid surface, dipstick therefor and its preparation
Assignee: Quidel Corp
•
Filing: 1984-05-04
•
Granted: —
•
Expires: 2004-05-04
Abstract
Abstract @ The inventive concept provides an immunoassay using an enzyme label, in which the detection of the unknown substance is performed colorimetrically directly upon a solid surface. Preferably, the surface is an impermeable surface of a dipstick. To detect antigen in a biologically derived fluid sample, a dipstick containing bound antibody may be contacted with the sample and with a soluble enzyme-labeled antibody, to cause the antigen to bind to both the immobilized antibody and the labeled antibody on the surface. After separation of unreacted reagents, the solid surface is contacted with a substrate which converts from a soluble form to an insoluble colored form in the presence of the enzyme and deposits upon the surface of the solid surface. The solid surface is separated from the solution. The sandwich immunoassay technique may also be employed to detect antibody in the sample by reversing the roles of the antigen and antibody. The system is also applicable to a competitive binding technique. The invention further includes a colored dipstick produced by this means.
Inventors
- 👤 Henry Garrett Wada
- 👤 Sarah R. Baxter
- 👤 Douglas D. Rundle
- 👤 Kenneth C. Kasper
- 👤 John C. Lankford
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 11:58
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54306; G01N33/54366; G01N33/74
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
131 words
1 . A method for the colorimetric immunoassay of an immunologically reactive substance to be detected in a fluid sample, comprising contacting said sample with a solid surface adapted to immobilize substance to be detected thereon from said sample and using said surface to immobilize an enzyme labeled diagostic reagent for said substance to be detected in an amount related to the amount of said substance which has been immobilized, contacting the resulting solid material with a solution of a substrate for said enzyme which is converted thereby into an insoluble colored form and allowing said insoluble colored form to deposit on said resulting solid material to impart thereto a visually discerrible color related to the presence of said substance, and separating the resulting colored solid material from said substrate solution.
Claim 2
Dependent Claim
131 words
1 . A method for the colorimetric immunoassay of an immunologically reactive substance to be detected in a fluid sample, comprising contacting said sample with a solid surface adapted to immobilize substance to be detected thereon from said sample and using said surface to immobilize an enzyme labeled diagostic reagent for said substance to be detected in an amount related to the amount of said substance which has been immobilized, contacting the resulting solid material with a solution of a substrate for said enzyme which is converted thereby into an insoluble colored form and allowing said insoluble colored form to deposit on said resulting solid material to impart thereto a visually discerrible color related to the presence of said substance, and separating the resulting colored solid material from said substrate solution.
Claim 3
Dependent Claim
162 words
A method as claimed in claim 1 which comprises (a) contacting said sample containing said substance to be detected with a solid phase comprising immobilized anti-substance bound in a layer to said solid surface, and with either soluble enzyme-labeled anti-substance or with free enzyme-labeled substance of the same type as said said substance to be detected thereby to cause an amount of the enzyme label to be immobilized which is related to the amount of said substance to be detected in the sample; (b) separating the resulting solid phase from step (a) from liquid phase; (c) contacting the separated solid phase from step (b) with a solution containing soluble substrate for the enzyme to cause the substrate to be converted into an insoluble colored form which deposits onto the solid phase to impart a visually discernible color to it related to the presence of said substance to be detected in the sample; and (d) separating said solid phase from said substrate solution.
Claim 4
Dependent Claim
27 words
A method as claimed in claim 2, wherein the immobilized anti-substance is a monoclonal antibody and/or an enzyme-labeled anti-substance is used which is an enzyme-labeled monoclonal antibody.
Claim 5
Independent Claim
43 words
A method as claimed in any one of claims 1 to 3, wherein said substance to be detected is human chorionic gonadotropin, the method being used for the detection of pregnancy, or luteinizing hormone, the method being used for the detection of ovulation.
Claim 6
Independent Claim
35 words
A method as claimed in any one of claims 1 to 4, wherein said substrate is uncolored prior to contact with the enzyme and converts to colored insoluble form in the presence of the enzyme.
Claim 7
Independent Claim
24 words
A method as claimed in any one of claims 1 to 5, wherein said solid surface is a reaction surface portion of a dipstick.
Claim 8
Independent Claim
189 words
A method as claimed in any one of claims 1 to 6 which is a sandwich-type method for the colorimetric immunoassay of antigen to be detected in a biologically derived fluid sample using a solid surface, comprising the steps of (a) contacting said biologically derived fluid sample containing antigen to be detected with a solid phase comprising immobilized antibody bound in a layer to a solid surface, and with soluble enzyme-labeled antibody, said immobilized antibody and enzyme-labeled antibody being immunologically reactive with said antigen, to cause said antigen to bind immunologically to both said immobilized antibody and said labeled antibody on said solid phase; (b) separating the solid phase from the solution containing unreacted soluble enzyme labeled antibody; (c) contacting the separated solid phase from step (b) with a solution containing soluble substrate for the enzyme to cause the substrate to be converted into insoluble colored form which deposits onto the solid phase to impart a visually discernible color to it as an indication of the presence of the antigen to be detected in the biologically derived fluid sample; and (d) separating said solid phase from said substrate solution.
Claim 9
Independent Claim
185 words
A method as claimed in any one of claims 1 to 6 which is a competitive method for the colorimetric immunoassay of antigen to be detected in a biologically-derived fluid sample using a solid surface, comprising the steps of (a) contacting immobilized antibody found in a layer to a solid surface forming a solid phase with said biologically derived fluid sample containing antigen to be detected and with free enzyme-labeled antigen of the same type as said antigen to be detected, to cause a competitive immunological reaction between said immobilized antibody and said antigen to be detected and enzyme-labeled antigen; (b) separating the reacted solid phase of step (a) from the liquid phase; (c) contacting the separated solid phase from step (b) with a solution containing soluble substrate for the enzyme to cause the substrate to be converted into insoluble colored form which deposits onto the solid phase to impart a visually discernible color to it as an inverse indication of the amount of the antigen to be detected in the biologically derived fluid sample; and (d) separating said solid phase from said substrate solution.
Claim 10
Dependent Claim
62 words
A reacted dipstick for an immunoassay including a solid reaction surface portion to which is bound consecutive layers of antibody immunologically bonded to antigen which is immunologically bonded to enzyme-labeled antibody, and a visually discernible colored substrate precipitated onto said consecutive layers, said substrate having been converted from a soluble to a precipitated colored form due to the presence of said enzyme.
Claim 11
Dependent Claim
62 words
A reacted dipstick for an immunoassay including a solid reaction surface portion to which is bound consecutive layers of antibody immunologically bonded to antigen which is immunologically bonded to enzyme-labeled antibody, and a visually discernible colored substrate precipitated onto said consecutive layers, said substrate having been converted from a soluble to a precipitated colored form due to the presence of said enzyme.
Claim 12
Dependent Claim
61 words
A reacted dipstick for an immunoassay including a solid reaction surface portion to which is bound a layer of antibody, at least a portion of which is immunologically bonded to enzyme-labeled antigen, and visually discernible colored substrate precipitated onto said layer, said substrate having been converted from a soluble to a precipitated colored form due to the presence of said enzyme.
Claim 13
Dependent Claim
61 words
A reacted dipstick for an immunoassay including a solid reaction surface portion to which is bound a layer of antibody, at least a portion of which is immunologically bonded to enzyme-labeled antigen, and visually discernible colored substrate precipitated onto said layer, said substrate having been converted from a soluble to a precipitated colored form due to the presence of said enzyme.
Claim 14
Dependent Claim
21 words
A reacted dipstick as claimed in claim 9 or claim 10, wherein the antigen is human chorionic gonadotropin or luteinzing hormone.
Claim 15
Dependent Claim
30 words
A process for forming a reacted dipstick as claimed in any one of claims 9 to 11 comprising carrying out the steps of a method as claimed in claim 6.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.