Comet assay – a sensitive method for measuring DNA damage and repair

Abstract

DNA damage is recognised as the first step in the process of carcinogenesis, induced by endogenous or environmental agents. At low levels, it is best detected with the comet assay (single cell gel electrophoresis), a method based on electrophoresis of lysed cells embedded in agarose; the amount of DNA migrating out to form a comet-like tail indicates the frequency of DNA breaks. Including a digestion with lesion-specific enzymes allows measurement of oxidised or alkylated bases, and UV-induced damage. The comet assay has applications in human biomonitoring, genotoxicity testing, basic research in DNA damage and repair, and environmental monitoring for effects of pollutants.

Keywords

• dna damage
• dna repair
• comet assay
• single cell gel electrophoresis
• genotoxicity
• biomonitoring