Randomly distributed DNA double-strand breaks as measured by pulsed field gel electrophoresis: a series of explanatory calculations.

The aim of this article is to characterize expressions of relevance to the interpretation of pulsed field gel electrophoresis (PFGE) experiments where randomly distributed double-strand breaks (DSBs) are detected as smears of DNA fragments. Specifically, equations for conversion of percentages of fragments in defined size ranges to DSBs were derived. Several models have been used, one of which is based on theoretically fragmented DNA from the fission yeast Schizosaccharomyces pombe, which has three PFGE separable chromosomes.