SOS chromotest, a direct assay of induction of an SOS function in Escherichia coli K-12 to measure genotoxicity.
- 1 October 1982
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 79 (19), 5971-5975
- https://doi.org/10.1073/pnas.79.19.5971
Abstract
The SOS chromotest, a bacterial test for detecting DNA-damaging agents, is evaluated. It is a colorimetric assay based on the induction by these agents of the SOS function sfiA, whose level of expression is monitored by means of a sfiA::lacZ operon fusion. The response is rapid (a few hours), and does not require survival of the tester strain. Dose-response curves for various chemicals include a linear region. The slope of this region is taken as a measure of the SOS inducing potency. Comparison for a number of substances of known genotoxicity of the SOS inducing potency determined in the SOS chromotest with the mutagenic potency determined in the Salmonella assay (mutatest) revealed a striking quantitative correlation over more than 7 orders of magnitude. The sensitivity of the SOS chromotest (lowest amount detected) is equal to that of the mutatest and generally 4-40 times higher than that of a phage induction assay (inductest). From a practical point of view these observations contribute to the validation of the SOS chromotest as a test for detecting genotoxins and in particular genotoxic carcinogens. Mutagenic potency measured in the mutatest reflects the level of induction of an SOS function and most genotoxins are inducers of the SOS response in bacteria. [This study may be applicable to human health.].This publication has 32 references indexed in Scilit:
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