| abstract |
A method for detecting or quantitating a mutagenic substratance in a sample includes culturing a host microorganism transformed with a recombinant gene comprising an SOS gene and genes expressing luciferase activity and optionally genes expressing an enzyme which catalyzes the production of a substrate for luciferase, positioned downstream of the SOS gene, in a medium to which the sample is added; and measuring a luminescence generated by expression of the gene expressing luciferase activity. The method is sensitive, accurate and non-time consuming; and gene systems used for said method, i.e., a recombinant gene comprising an SOS gene expressed when a DNA is damaged and a gene expressing luciferase activity positioned downstream of the SOS gene, and a host microorganism transformed with said recombinant gene. Preferably the recombinant gene further comprises a gene expressing an enzyme which catalyses the production of a substrate for the luciferase in the down stream of the SOS gene. |