US3862885A
Expired / Lapsed
US
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Determination of uric acid in blood with uricase
Assignee: Ono Pharmaceutical Co Ltd
•
Filing: 1971-11-19
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Granted: 1975-01-28
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Expires: 1991-11-19
Abstract
Abstract A process for quantitively determining uric acid in blood with uricase characterized by making microbe-originated uricase act on uric acid in blood in the presence of a catalase inhibitor and a buffer effective to maintain the pH at 5.5 to 7.0 and measuring the quantity of the generated hydrogen peroxide under a condition of a pH of 4.0 to 7.0 in the presence of an anionic surface active agent, a chromogen developing a color with hydrogen peroxide and a substance having a function of separating free oxygen from hydrogen peroxide and catalysing the oxidation of the chromogen.
Inventors
- 👤 Kunio Kano
- 👤 Naohiro Kayama
- 👤 Hiroshi Terashima
- 👤 Yoshitaka Nakagiri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:46
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/62
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
22 words
The process as recited in claim 1 wherein a buffer which maintains a pH range of 5.7-6.5 is added to the blood.
Claim 2
Dependent Claim
21 words
The process as recited in claim 2 wherein the buffer is a phosphate buffer, a citrate buffer or an acetate buffer.
Claim 3
Dependent Claim
26 words
The process as recited in claim 1 wherein the hydrogen peroxide is measured by contacting the hydrogen peroxide with a chromogen whereby a color is produced.
Claim 4
Dependent Claim
18 words
The process as recited in claim 4 wherein the chromogen is o-tolidine, 2,7-diaminofluorene, dimethyl-p-phenylenediamine, diethyl-p-phenylenediamine, o-dianididine, or o-aminophenol.
Claim 5
Dependent Claim
25 words
The process as recited in claim 4 wherein the hydrogen peroxide is contacted with the chromogen in a buffer solution having a pH of 4-7.
Claim 6
Dependent Claim
14 words
The process as recited in claim 6 wherein the pH is 4 - 4.5.
Claim 7
Dependent Claim
16 words
The process as recited in claim 1 wherein a catalase inhibitor is added to the blood.
Claim 8
Dependent Claim
19 words
The process as recited in claim 8 wherein the catalase inhibitor is sodium azide, potassium cyanide, or sodium cyanide.
Claim 9
Dependent Claim
16 words
The process as recited in claim 4 wherein a dispersing agent is added to the chromogen.
Claim 10
Dependent Claim
19 words
The process as recited in claim 10 wherein the dispersing agent is polyethylene glycol, polyvinyl alcohol, or polyvinyl pyrrolidone.
Claim 11
Dependent Claim
15 words
The process as recited in claim 1 wherein copper ions are added to the blood.
Claim 12
Dependent Claim
24 words
The process as recited in claim 4 wherein the hydrogen peroxide is contacted with the chromogen in the presence of a chromogen oxidation catalyst.
Claim 13
Dependent Claim
12 words
The process as recited in claim 13 wherein the catalyst is peroxidase.
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) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |