History of comet assay

This was first introduced by Ostling and Johanson in 1984. This was a neutral assay in which the lysis and electrophoresis were done under neutral conditions. Staining was done with acridine orange. The image obtained looked like a “comet” with a distinct head, comprising of intact DNA and a tail, consisting of damaged or broken pieces of DNA hence the name “Comet” Assay. The approach of Ostling and Johanson was based on previous work published by P Cook et al., 1976, who developed a method for investigating nuclear structure based on the high salt lysis of cells in the presence of non-ionic detergents.
The more versatile alkaline method of the comet assay was developed by N.P. Singh and co workers in 1988. This method was developed to measure low levels of strand breaks with high sensitivity. Several reviews have been published in recent years to highlight the procedures, advantages and limitations of this assay in genotoxicological, ecotoxicological and biomonitoring studies (Collins, 2004; Dixon et al., 2002; Fairbairn et al. 1995; Lee and Steinert, 2003). The assay has also been successfully implemented in plant cells under laboratory conditions (Gichner et al., 2004, Gichner et al., 2006).
From-comet assay interest group.