Modification of the Comet assay for the detection of DNA strand breaks in extremely small tissue samples

Abstract

We modified the Comet assay to enable the quantification of DNA strand breakage in individual cells of extremely small tissue samples. This modification was used to analyze cells isolated from the ectoplacental cone and egg cylinder of mouse embryos at embryonic day 7.5. We detected more naturally occurring DNA strand breaks and a higher number of apoptotic cells in the ectoplacental cone compared with the egg cylinder.