A Study on quantitative analysis of heavy-ion-induced DNA double-strand breaks; A Problem of conventional protocol using pulsed-field gel electrophoresis

Yokota, Yuichiro; Funayama, Tomoo; Muto, Yasuko; Sakashita, Tetsuya; Kikuchi, Masahiro; Kobayashi, Yasuhiko

Heavy-ion-induced DNA double-strand breaks (DSBs) have been focused to reveal the underlying mechanism of the well-known findings that relative biological effectiveness is greater in high-LET heavy ions than in low-LET radiation. Since 1990s, DSBs have been quantified with pulsed-field gel electrophoresis (PFGE) technology. In conventional studies, DNA preparation from irradiated cells was performed in agarose plugs for avoiding excess DNA fragmentation during experimental procedures. However, we have found here that DNA fragments are partly lost from the agarose plug during DNA preparation. This makes difficult to reveal the total DSB yield in irradiated cells.