Evaluation of the yeast DEL assay with 10 compounds selected by the International Program on Chemical Safety for the evaluation of short-term tests for carcinogens.

The Saccharomyces cerevisiae DEL assay detects a wide variety of nonmutagenic carcinogens (Schiestl et al. (1989) Carcinogenesis, 10, 1445-1455). This study shows the effect on DEL recombination of 8 carcinogenic compounds (o-toluidine, hexamethylphosphoramide, safrole, acrylonitrile, benzene, diethylhexylphthalate, phenobarbital and diethylstilbestrol) and 2 noncarcinogenic compounds (caprolactam and benzoin). These chemicals have been selected by the Program on Chemical Safety for the evaluation of short-term tests for carcinogens, because sufficient carcinogenicity data for these compounds exist, and because they are difficult to detect with the Salmonella assay. 5 of 8 carcinogens reproducibly gave a strong positive response and the noncarcinogen benzoin was negative. Thus, 60% of the chemicals tested in this study have been correctly identified with the DEL assay compared to only 20% with the Salmonella assay.