In Vitro Mammalian Cell Gene Mutation Kit

The in vitro mammalian cell gene mutation test can be used to detect hypoxanthine-guanine phosphoribosyl transferase (HPRT) gene mutations induced by chemical substances in suitable cell lines including CHO and V79 of Chinese hamster cells. Mutant cells deficient in Hprt enzyme activity in the HPRT test are resistant to the cytostatic effects of the purine analogue 6-thioguanine (TG). The Hprt proficient cells are sensitive to TG, which causes the inhibition of cellular metabolism and halts further cell division. Thus, mutant cells are able to proliferate in the presence of TG, whereas normal cells, which contain the Hprt (in the HPRT test) enzyme, are not. Cells in suspension or monolayer cultures are exposed to the test chemical, both with and without an exogenous source of metabolic activation, for a suitable period of time, and then sub-cultured to determine cytotoxicity and to allow phenotypic expression prior to mutant selection. Cytotoxicity is determined by relative survival (RS), i.e., cloning efficiency measured immediately after treatment and adjusted for any cell loss during treatment as compared to the negative control. The treated cultures are maintained in growth medium for a sufficient period of time, characteristic of each cell type, to allow near-optimal phenotypic expression of induced mutations. Following phenotypic expression, mutant frequency is determined by seeding known numbers of cells in medium containing the selective agent to detect mutant colonies, and in medium without selective agent to determine the cloning efficiency (viability). After a suitable incubation time, colonies are counted. Mutant frequency is calculated based on the number of mutant colonies corrected by the cloning efficiency at the time of mutant selection.

Please contact us at for specific academic pricing.