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US4629693A
Expired / Lapsed
US
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Sensitivity in fluorescence assays in icteric samples
Assignee: Siemens Healthcare Diagnostics GmbH Germany
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Filing: 1984-03-27
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Granted: 1986-12-16
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Expires: 2004-03-27
Abstract
Abstract Enhanced sensitivity in fluorescent assays employing NADH or NADPH is obtained, particularly in icteric samples, by employing excitation light at a wave length range below about 400 nm and reading emitted light above about 500 nm.
Inventors
- 👤 Pyare Khanna
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:02
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/58; G01N33/581; C; C12; C12Q; C12Q1/00; C12Q1/26; C12Q1/32; Y; Y10; Y10S; Y10S435/00; Y10S435/962; Y10S436/00; Y10S436/805
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
122 words
In an enzyme immunoassay method for the determination of an analyte in an icteric blood sample suspected of containing said analyte, said method comprising combining in an assay medium said sample and assay reagents and irradiating said medium, said method involving the production or oxidation of NADH or NADPH in said medium and employing fluorescent detection of NADH or NADPH wherein a change in fluorescence is related to the amount of analyte in said sample, the improvement which comprises irradiating said medium containing said sample and said assay reagents with light below 400 nm to excite NADH or NADPH produced or oxidized in said assay medium and detecting the fluorescence of NADH or NADPH at a wavelength at or above 500 nm.
Claim 2
Dependent Claim
122 words
In an enzyme immunoassay method for the determination of an analyte in an icteric blood sample suspected of containing said analyte, said method comprising combining in an assay medium said sample and assay reagents and irradiating said medium, said method involving the production or oxidation of NADH or NADPH in said medium and employing fluorescent detection of NADH or NADPH wherein a change in fluorescence is related to the amount of analyte in said sample, the improvement which comprises irradiating said medium containing said sample and said assay reagents with light below 400 nm to excite NADH or NADPH produced or oxidized in said assay medium and detecting the fluorescence of NADH or NADPH at a wavelength at or above 500 nm.
Claim 3
Dependent Claim
47 words
The method of claim 1 wherein said method involves employing in said assay medium glucose-6-phosphate dehydrogenase, glucose-6-phosphate and NAD or NADP and wherein said glucose-6-phosphate dehydrogenase is employed as a catalyst and reacts with said glucose-6-phosphate and as a result thereof said NADH or NADPH is produced.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein said assay method involves the measurement of a hapten.
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein said method is a homogeneous assay.
Claim 6
Dependent Claim
50 words
The method of claim 1 wherein said method involves employing in said assay medium a dehydrogenase, a substrate for said dehydrogenase, and NAD or NADP and wherein said dehydrogenase is employed as a catalyst and reacts with said substrate and as a result thereof said NADH or NADPH is produced.
Claim 7
Dependent Claim
154 words
In an enzyme immunoassay method for the determination of an analyte in an icteric blood sample suspected of containing said analyte, said method comprising combining in an assay medium said sample and assay reagents and irradiating said medium, said method involving employing in said assay medium an enzyme, a substrate for said enzyme, and employing NAD or NADP as a cofactor for said enzyme, said method involving production of the reduced form of NAD or NADP in said medium and employing detection of the reduced form of NAD or NADP in said medium by measuring the light emitted by said reduced form of NAD or NADP, the improvement which comprises irradiating said assay medium containing said sample and said assay reagents suspected of containing said reduced form of NAD or NADP with light below about 400 nm and measuring the light emitted by said reduced form at a wavelength at or above 500 nm.
Claim 8
Dependent Claim
154 words
In an enzyme immunoassay method for the determination of an analyte in an icteric blood sample suspected of containing said analyte, said method comprising combining in an assay medium said sample and assay reagents and irradiating said medium, said method involving employing in said assay medium an enzyme, a substrate for said enzyme, and employing NAD or NADP as a cofactor for said enzyme, said method involving production of the reduced form of NAD or NADP in said medium and employing detection of the reduced form of NAD or NADP in said medium by measuring the light emitted by said reduced form of NAD or NADP, the improvement which comprises irradiating said assay medium containing said sample and said assay reagents suspected of containing said reduced form of NAD or NADP with light below about 400 nm and measuring the light emitted by said reduced form at a wavelength at or above 500 nm.
Claim 9
Dependent Claim
11 words
The method of claim 6 wherein the enzyme is glucose-6-phosphate dehydrogenase.
Claim 10
Dependent Claim
12 words
The method of claim 6 wherein the assay is for a hapten.
Claim 11
Dependent Claim
11 words
The method of claim 6 which is a homogeneous assay method.
Claim 12
Dependent Claim
11 words
The method of claim 6 wherein the enzyme is a dehydrogenase.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-15 | 1990-06-16 | 1990-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-15 | 1994-06-16 | 1994-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-15 | 1998-06-16 | 1998-12-16 | $7700.00 | Window Closed / Lapsed |