A Novel Yeast-Based Mutagenicity Screen

Many industrially relevant chemicals have incomplete mutagenicity or cytotoxicity data available. Current testing methods are often expensive and tedious. As an alternative to traditional mutagenicity assays such as the Ames test or the SOS Chromotest, we have developed a yeast-based mutagenicity screen. We have genetically engineered S. cerevisiae cells such that the promoter of a DNA-damage specific gene is regulating expression of green fluorescent protein (GFP). When these recombinant strains are exposed to mutagenic conditions, GFP is produced and the cells fluoresce. Fluorescence can be observed qualitatively or measured quantitatively with flow cytometry or a fluorescent plate reader. We are able to detect multiple types of DNA damage including alkylating agents, oxidative agents, and ionizing radiation. Optimum results are available in 4-6 hours, a great improvement over other assays. Additionally we are able to detect lower mutagenic concentrations than traditional assays.