A microanalytical variant of the SOS Chromotest for genotoxicological evaluation of natural and synthetic products

agents that can damage the dna in vivo have potential adverse effects on human health. they may induce transmissible mutations and cancer. sos chromotest is a sos transcriptional-fusion based assay, ？-galactosidase gene was located after a sos promoter, thus its enzymatic activity indicates the level of induction of sos response and the dna damage produced by chemical and physical mutagens, can be estimated. we presented and evaluated a microanalytical variant of the original sos chromotest for detecting genotoxicity of pigmented samples. we introduced two main modifications: we changed the colorimetric substrates for fluorescent ones and we worked at micro-analytical scale. the optimal ？-galactosidase substrate concentration used was 1.8 mm and 40 minutes as time reaction. this variant detected efficiently the genotoxicity of known mutagen and the natural pigmented extracts. the results are discussed in relation to the advantages to work at micronalytical scale, costs reduction, automatization of reading and its usefulness for the screening of a large variety of samples.