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EP0434800B1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Analytical assay method

Assignee: Behring Diagnostics Inc
•
Filing: 1990-06-19
•
Granted: 1993-11-18
•
Expires: 2010-06-19
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Abstract

Abstract A method for determining the amount of an analyte in a sample fluid utilizes a multilayer assay element which comprises at least one reagent layer and a light-blocking layer. The assay method includes the steps of optically reading a signal producing species, e.g. a fluorescent label, a first time before the sample fluid is applied to the assay element and a second time, at the same wavelength and in the same location within the assay element, after the sample fluid has been applied to the assay element and the sample analyte has interacted with the reagent(s) present in the assay element. The ratio of the two signals is taken and compared with that for known amounts of the analyte to determine the amount of analyte in the sample fluid.

Inventors

  • 👤 John J. Blackwood
  • 👤 Shai Inbar
  • 👤 Donna R. Maretsky

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-31 22:20
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6428; G01N33/00; G01N33/48; G01N33/50; G01N33/52; G01N33/525; G01N21/75; G01N2021/755; Y; Y10; Y10S; Y10S435/00; Y10S435/97; Y10S436/00; Y10S436/80; Y10T; Y10T436/00; Y10T436/10

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 136 words
A method for determining the presence of an analyte in a sample fluid comprising (a) distributing a sample of fluid across the surface of a multilayer assay element which comprises: i. a light-blocking layer which is permeable to said fluid; and ii. a reagent layer comprising a signal generating species. (b) obtaining a readout signal by irradiating said reagent layer with electromagnetic radiaticn which is in the absorption region of said signal generating species; (c) taking the ratio of said readout signal from step (b) to a readout signal obtained by irradiating said reagent layer with the same electromagnetic radiation used in step (b) prior to distributing said fluid sample in step (a); and (d) comparing said ratio with that obtained for known amounts of said analyte to determine the amount of analyte in said sample.
Claim 2
Dependent Claim 22 words
The method as defined in claim 1 wherein said assay element further includes a support which is transparent to said electromagnetic radiation.
Claim 3
Dependent Claim 43 words
The method as defined in claim 1 wherein said reagent layer includes an immobilized binding partner for said analyte and said signal generating species comprises a conjugate of a label bound to a moiety which is capable of binding to said binding partner.
Claim 4
Dependent Claim 21 words
The method as defined in claim 3 wherein said moiety bound to said label is said analyte or an analogue thereof.
Claim 5
Dependent Claim 12 words
The method as defined in claim 3 wherein said label is fluorescent.
Claim 6
Dependent Claim 22 words
The method as defined in claim 2 wherein said assay element further includes a top layer arranged above said light blocking layer.
Claim 7
Dependent Claim 35 words
The method as defined in claim 2 wherein the ratio of the thickness of said reagent layer to that of the remainder of said assay element is from about 1:20 to about 1:100 or more.

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