The Level of Induced DNA Double-strand Breakage Correlates with Cell Killing after X-irradiation

Abstract

The neutral filter elution technique has been used to examine the relationship between X-ray-induced DNA double-strand breakage (dsb) and lethal lesions. The ratios of the different lesions produced by X-irradiation were varied by irradiation in the presence of different radiomodifiers, and in each case the same linear relationship between lethal lesions and induced DNA dsb was found. This relationship also held for cells given a hyperthermic treatment before irradiation. It is concluded that DNA dsb is probably the lethal lesion induced by ionizing radiation.