Mutagenicity and DNA Repair Potential of 15 Chemicals.

A research programme was established to construct a priority list of certain ordnance compounds for carcinogenic testing. As aids to this objective, a restricted battery of so-called short-term screening tests was used. In this initial part of the programme, 15 chemicals were tested. Five strains of Salmonella typhimurium were used in mutagenicity tests according to the techniques established by Ames et al, 1975 Mutation Res., 31 347. Two strains of Escherichia coli were used in DNA repair tests on plates and, where necessary, in liquid medium. This latter technique was used only if the plate test for DNA repair failed to produce toxicity in either strain. A third test used was the mitotic recombinogenic activity assay in the yeast, Saccharomyces cerevisiae D5. Each test was conducted in vitro and in tissue liver mediated assays. Liver for these tests came from young, adult, male Fischer 344 rats following enzyme induction with aroclor 1254. Post-mitochondrial supernatant fluid fractions S-9 were stored in liquid nitrogen -192 deg C for up to one month before they were discarded.