US3816263A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biological test
Assignee: Individual
•
Filing: 1972-03-06
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Granted: 1974-06-11
•
Expires: 1992-03-06
Abstract
Abstract A method of testing a substance for carcinogenic activity which comprises contacting the substance with isolated cell membranes having masked rearrangase activity and after a predetermined interval of time testing the cell membranes for rearrangase activity. This method enables substances to be screened for possible carcinogenic activity. A test kit is also described.
Inventors
- 👤 D Williams
- 👤 B Rabin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:34
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/5005; G01N33/5008; G01N33/5014; G01N33/53; G01N33/575; Y; Y10; Y10S; Y10S435/00; Y10S435/81
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
183 words
A method of testing a substance for carcinogenic activity which comprises the steps of: a. adding, after a predetermined time, a sample of a solution comprising the substance to be tested, reduced nicotinamide adenine dinucleotide phosphate and isolated cell membranes having masked rearrangase activity and an RNA/protein ratio within the range of 0.14-0.19, in a sucrose-magnesium chloride-potassium chloride-tris (hydroxymethyl) aminomethane buffer solution, to a second solution, said second solution having been prepared by first making a solution of a protein having random disulfide linkages capable of rearrangement by rearrangase to an enzymatically active form in a suitable electrolyte, and thereafter adjusting the pH of said second solution with a suitable base, and then adding a mercaptan to said second solution b. adding a sample of the resulting mixed solution (a) after a predetermined time to a sample of a third solution comprising a substrate for measuring the degree of enzymatic activity of the rearranged protein in a suitable electrolyte; c. assaying the degree of rearrangement of the protein in the resulting solution; and d. determining the carcinogenic activity from said degree of rearrangement.
Claim 2
Dependent Claim
36 words
The method of claim 2 wherein the protein having random disulfide linkages is randomly oxidized ribonuclease and the substrate for measuring the degree of enzymatic activity is cytidine 2'', 3''-cyclic phosphoric acid or a salt thereof.
Claim 3
Dependent Claim
26 words
The method of claim 3 Wherein the suitable electrolyte is potassium chloride and the suitable base for adjusting the pH of the second solution is borax.
Claim 4
Dependent Claim
69 words
A test kit for use in determining possible carcinogenic activity in a substance which comprises: a. NADPH or a system generating NADPH b. A sucrose-magnesium chloride-potassium chloride tris buffer solution c. A protein having random disulphide linkages capable of rearrangement by rearrangase to an enzymatically active form. d. a mercaptan e. A substrate for measuring the degree of enzymatic activity of the enzymatically active form of said protein (c).
Claim 5
Dependent Claim
12 words
A test kit as claimed in claim 5 including isolated cell membranes.
Claim 6
Dependent Claim
31 words
A test kit as claimed in claim 5 in which the protein (c) is randomly oxidized ribonuclease and the substrate (e) is cytidine 2'', 3''-cyclic phosphoric acid or a salt thereof.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |