Detection of γ-Irradiation Induced DNA Damage and Radioprotection of Compounds in Yeast Using Comet Assay

Abstract

The single cell gel electrophoresis assay (SCGE), a very rapid and sensitive method, has been applied to follow γ-irradiation induced DNA damage in budding yeast, Saccharomyces cerevisiae. Spheroplasting the γ-irradiated yeast cells by enzyme glusulase, before subjecting them to electrophoresis, resulted in a well-defined appearance of comets. Yeast comets look quite different from mammalian comets. A linear relationship was observed between the doses of irradiation and the tail moments of comets. These studies were extended to follow the action of known radio-protectors, i.e., caffeine and disulfiram. The results revealed the usefulness SCGE as applied to yeast in studies of the γ-irradiation-induced DNA breaks and also radio-protection by chemicals at doses that are not feasible with other eukaryotes.