In vitro studies of chemical mutagens and carcinogens. I. Stability studies in cell culture medium.

A quantitative microbial assay was used to study the stability of known mutagenic and carcinogenic compounds in cell culture medium. Ten direct-acting carcinogens, when incubated in culture medium with 15% fetal bovine serum at pH 7.2-7.4 and 37 degrees C, became inactive at varying rates. Biologic half-lives of the test compounds ranged from 8 minutes to 67 hours. In contrast, six procarcinogens showed no significant inactivation after 3 weeks' incubation. The biologic half-lives of each compound were presented, and the significance of these findings as they relate to cell culture carcinogenesis and mutagenesis assays was discussed.