US4098574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glucose detection system free from fluoride-ion interference
Assignee: Eastman Kodak Co
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Filing: 1977-08-01
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Granted: 1978-07-04
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Expires: 1997-08-01
Abstract
Abstract An improved multilayer element for detecting glucose in samples of biological fluid which may contain with fluoride ion as a contaminant or preservative is described. The improved element comprises a buffered Trinder's reagent, which reagent comprises glucose oxidase, peroxidase, 4-aminoantipyrine and a phenolic or naphtholic coupler, which is buffered to a pH between about 4.5 and about 6.0. Such a buffering reduces any interference which may be due to fluoride ion present in the sample under analysis.
Inventors
- 👤 Glen Marshall Dappen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:01
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/54; Y; Y10; Y10T; Y10T436/00; Y10T436/14; Y10T436/142222; Y10T436/143333; Y10T436/144444
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
115 words
In a method for assaying for glucose in aqueous liquids by applying a sample of the aqueous liquid to a test element comprising a spreading layer and a reagent layer containing a reagent composition comprising a buffer, glucose oxidase, a substance having peroxidative activity and an indicator composition comprising 4-aminoantipyrine and a phenolic or naphtholic coupler such that glucose contained in the liquid sample is oxidized in the presence of said reagent composition to produce a colored product, the improvement comprising performing the said assay at a pH of between about 4.5 and 6.0 to reduce or eliminate interference with the assay due to fluoride ion which may be contained in the aqueous liquid sample.
Claim 2
Dependent Claim
115 words
In a method for assaying for glucose in aqueous liquids by applying a sample of the aqueous liquid to a test element comprising a spreading layer and a reagent layer containing a reagent composition comprising a buffer, glucose oxidase, a substance having peroxidative activity and an indicator composition comprising 4-aminoantipyrine and a phenolic or naphtholic coupler such that glucose contained in the liquid sample is oxidized in the presence of said reagent composition to produce a colored product, the improvement comprising performing the said assay at a pH of between about 4.5 and 6.0 to reduce or eliminate interference with the assay due to fluoride ion which may be contained in the aqueous liquid sample.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein said substance having peroxidative activity is peroxidase.
Claim 4
Dependent Claim
10 words
The method of claim 1 wherein said coupler is 7-hydroxy-1-naphthol.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein the buffer is selected from the group consisting of dimethylglutaric acid, succinic acid, potassium acid phthalate, malic acid, and mixed phosphate-citrate buffer.
Claim 6
Dependent Claim
62 words
In an integral element for the determination of glucose in aqueous liquids comprising a spreading layer and a reagent layer in fluid contact under conditions of use and containing as the glucose determining reagent composition Trinder's reagent the improvement comprising the inclusion of a buffer which maintains the pH of the reagent composition between about 4.5 and 6.0 under conditions of use.
Claim 7
Dependent Claim
62 words
In an integral element for the determination of glucose in aqueous liquids comprising a spreading layer and a reagent layer in fluid contact under conditions of use and containing as the glucose determining reagent composition Trinder's reagent the improvement comprising the inclusion of a buffer which maintains the pH of the reagent composition between about 4.5 and 6.0 under conditions of use.
Claim 8
Dependent Claim
13 words
The element of claim 5 wherein said substance having peroxidative activity is peroxidase.
Claim 9
Dependent Claim
10 words
The element of claim 5 wherein said coupler is 7-hydroxy-1-naphthol.
Claim 10
Dependent Claim
28 words
The element of claim 5 wherein the buffer is selected from the group consisting of dimethylglutaric acid, succinic acid, potassium acid phthalate, malic acid, and mixed phosphate-citrate buffer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |