Pulsed-field gel electrophoresis in the measurement of DNA double-strand break repair in xrs-6 and CHO cell lines: DNA degradation under some conditions interferes with the assessment of double-strand break rejoining.

Pulsed-field gel electrophoresis (PFGE) is a sensitive assay for DNA double-strand breaks (DSBs). The application of PFGE to the measurement of DSB rejoining requires attention to conditions after irradiation. When cells are irradiated and incubated while encapsulated in agarose, DNA DSB rejoining appears incomplete or absent due to DNA degradation artifacts. Using PFGE we have measured the DSB rejoining defect in xrs-6 cells and shown how DNA degradation can affect the results.