Patent US4352880A successfully refreshed from Google Patents.
US4352880A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffusion bioassay for the quantitative determination of mutagenicity
Assignee: Massachusetts Institute of Technology
•
Filing: 1979-09-17
•
Granted: 1982-10-05
•
Expires: 1999-09-17
Abstract
Abstract A quantitative bioassay employing the well known diffusion bioassay is described herein. The bioassay allows the calculation of the minimum concentration of a test agent which produces mutation in a tester strain of cells employed in the diffusion bioassay. A novel method for determining the stability of the agent tested in the test environment is also described.
Inventors
- 👤 Tamara E. Awerbuch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:11
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/02; C12Q1/025
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
106 words
A bioassay for determining the degree of mutagenicity of an agent, comprising: a. forming a culture of living cells, said cells being a tester strain for mutagenesis; b. applying a spot of test agent in known concentration to said culture whereby said test agent diffuses outwardly from said spot to form a ring-shaped mutagenic band in which viable mutant cells are produced, said ring-shaped mutagenic band being concentric to the spot of test agent; c. measuring the length of a radius from said spot to said ring-shaped mutagenic band; and, d. employing the length of said radius to determine the degree of mutagenicity of said agent.
Claim 2
Dependent Claim
106 words
A bioassay for determining the degree of mutagenicity of an agent, comprising: a. forming a culture of living cells, said cells being a tester strain for mutagenesis; b. applying a spot of test agent in known concentration to said culture whereby said test agent diffuses outwardly from said spot to form a ring-shaped mutagenic band in which viable mutant cells are produced, said ring-shaped mutagenic band being concentric to the spot of test agent; c. measuring the length of a radius from said spot to said ring-shaped mutagenic band; and, d. employing the length of said radius to determine the degree of mutagenicity of said agent.
Claim 3
Dependent Claim
14 words
A bioassay of claim 1 wherein said test agent comprises a water-soluble chemical substance.
Claim 4
Dependent Claim
27 words
A bioassay of claim 2 wherein said radius extends from the center of said spot of test agent to the outside perimeter of said ring-shaped mutant band.
Claim 5
Dependent Claim
14 words
A bioassay of claims 1 or 3 wherein said living cells comprise human cells.
Claim 6
Dependent Claim
14 words
A bioassay of claims 1 or 3 wherein said living cells comprise bacterial cells.
Claim 7
Independent Claim
176 words
A method for determining the half-lifetime (τ1/2) of a potential mutagenic agent in a cell culture environment, comprising: a. forming a culture of living cells, said cells being a tester strain for mutagenesis; b. applying a spot of test agent in known concentration to said culture whereby said test agent diffuses outwardly from said spot to form a ring-shaped mutagenic band in which viable mutant cells are produced, said ring-shaped mutagenic band being concentric to said spot of test agent; c. measuring the length of a radius extending from the center of said spot to the outer perimeter of said ring-shaped mutagenic band; d. repeating steps a-c a sufficient number of times with different initial concentrations of test agent to allow a plot to be constructed relating the initial concentration of agent to the length of radius measured; e. constructing a plot relating the initial concentration to the length of the radius measured for a plurality of initial concentrations; and, f. determining the slope of said plot as an indication of the half-lifetime of said agent.
Claim 8
Independent Claim
176 words
A method for determining the half-lifetime (τ1/2) of a potential mutagenic agent in a cell culture environment, comprising: a. forming a culture of living cells, said cells being a tester strain for mutagenesis; b. applying a spot of test agent in known concentration to said culture whereby said test agent diffuses outwardly from said spot to form a ring-shaped mutagenic band in which viable mutant cells are produced, said ring-shaped mutagenic band being concentric to said spot of test agent; c. measuring the length of a radius extending from the center of said spot to the outer perimeter of said ring-shaped mutagenic band; d. repeating steps a-c a sufficient number of times with different initial concentrations of test agent to allow a plot to be constructed relating the initial concentration of agent to the length of radius measured; e. constructing a plot relating the initial concentration to the length of the radius measured for a plurality of initial concentrations; and, f. determining the slope of said plot as an indication of the half-lifetime of said agent.
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) | 1985-10-04 | 1986-04-05 | 1986-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-04 | 1990-04-05 | 1990-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-04 | 1994-04-05 | 1994-10-05 | $7700.00 | Window Closed / Lapsed |