METHOD TO DETECT GENOTOXICITY OF CHEMICAL SUBSTANCES Russian patent published in 2002 - IPC

FIELD: ecology, genetic toxicology. SUBSTANCE: the method deals with testing the chemical substances which contaminate the environment. The method includes incubation of the tested substances by using a liquid nutritive medium with plasmidcarrying E.coli strain in which Lux operon is controlled by a SOS- promoter (SOS-lux strain). Separately, this substance is incubated with a strain (Lux- strain) the genotype of which is similar to that of a SOS-lux strain, but Lux operon is controlled by a constitutive promoter. It is measured a bioluminescence intensity of a control cultures' suspension and those containing chemical substances under testing. It is determined an induction factor I and a luminescence suppression coefficient K by the following formula: I=Lc/Lk (1), K=Ic/Ik (2), where I - an induction factor, Lc - a luminescence intensity of a SOS-lux strain suspension which contains the chemical substance under testing, Lk - a luminescence intensity of a SOS-lux strain control suspension, K - a luminescence suppression coefficient, Ic - a luminescence intensity of a lux-strain suspension at the presence of the chemical substance under testing, Ik - a luminescence intensity of a lux-strain control suspension. Then, the induction factor should be corrected by the formula: I'=I/K, where I' - a corrected induction factor. EFFECT: higher accuracy in determining the genotoxicity of chemical substances due to correction of artefacts during testing both pure substances and natural mixtures. 2 tbl