Rate of double strand breaks of genome-sized DNA in tritiated water: Its dependence on tritium concentration and water temperature

抄録

The goal of this study is to establish a simple experimental system to examine the rate of double strand breaks (DSBs) of genome-sized DNA molecules under irradiation of β-rays from tritium under well-controlled conditions for the validation of computer simulation on interactions of biomolecules and ionizing radiation. Irradiation effects were insignificant at tritium concentration of 1300 Bq/cm³, indicating that the effects of β-rays were far smaller than those of oxidation and/or thermal motion at the low dose rate (4.3 μGy/h). Clear increase in DSB rate was observed at tritium concentrations of 3.0—4.0 MBq/cm³. The temperature dependence of DSB rate was examined by using the high concentration tritiated water.