US3732077A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and composition for determining bun
Assignee: Damon Corp
•
Filing: 1971-10-29
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Granted: 1973-05-08
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Expires: 1991-10-29
Abstract
Abstract Blood serum is tested for the presence of urea nitrogen by reacting urea present in the serum with an aqueous reagent having a pH of between 0.4 and 1.5 and containing diacetylmonoxime, phenazone, arsenic pentoxide and sulfuric acid. Reaction is effected by heating the serum-reagent mixture to 85* to 100* C., cooling and measuring the optical absorbance of the cooled mixture at a wavelength between 450 and 485 nm.
Inventors
- 👤 L Foster
- 👤 J Hochholzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:18
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/62; Y; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/171538
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
65 words
The method of determining the presence of urea nitrogen in blood serum which comprises mixing a blood serum sample with the reagent of claim 1, heating the mixture between 85* and 100* C., cooling the mixture to room temperature and determining the optical density of the cooled mixture at a wavelength between 450 and 485 nm within about 15 minutes after the mixture is cooled.
Claim 2
Dependent Claim
16 words
The method of claim 2 wherein the pH of the reagent is between 0.4 and 1.5.
References Cited (Backward Citations)
US3511611A
Cited
US3567374A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |