Single cell gel electrophoresis (the comet assay) is a sensitive method for detecting DNA damage in the nucleus of virtually all types of eukaryotic cell. The principle of the assay is that DNA damage (i.e., DNA breaks) allows DNA in the nucleus to migrate within a gel, under electrophoresis; this process forms a “tail”, and the appearance of a comet. The more breaks, the greater the tail, which can be quantified, and the amount of damage determined. Unfortunately, the comet assay is time-consuming, labor intensive, and involves numerous sample manipulations, which risk the loss of samples. Researchers at the University of South Florida have devised a method that, unlike the convention where the electrophoresis step is performed horizontally, electrophoresis can be performed vertically. This development facilitates a host of improvements to the assay, including faster sample processing, lower risk of sample loss, smaller electrophoresis tank footprint, with integral cooling, and a decreased reagent requirement. The new assay format is amenable to all versions of the comet assay, including CometChip, and Comet/FLARE.
(1) Proposed electrophoresis tank, fluidics chambers, and slide carriers showing the vertical orientation of the slides. (2) Size comparison, our novel approach, and the conventional approach.