Estimation of DNA single-strand breaks by single cells gel electrophoresis in tumor cells

To estimate the frequency of single-strand breaks on a single cell level the so-called comet-assay (single cell gel electrophoresis) is a well-established technique. We present a modified protocol suitable for testing primary tumors, a kind of tissue very uneasy to be analysed in former single cell gel electrophoresis assays. Tumor cells of 12 studied cases showed a typical dose-rate effect on in vitro irradiatiation with different X-ray doses, as observed in peripheral blood leukocytes. Interestingly, the repair capability of primary tumor cells was lower than that of peripheral blood leukocytes of the same patients. (C) 1998 Elsevier Science B.V. All rights reserved.