DNA Strand Breakage by X-Irradiation

Abstract
Bacteriophage DNA has been X-irradiated both free in solution and in the phage head and in several solvents. By ultracentrifugal analysis survival curves for the percentage of unbroken double-stranded and single-stranded molecules as a function of dose have been obtained. From the D37 the rates of production of double-strand and single-strand breaks per rad per unit molecular weight have been derived. The effect of a variety of conditions has also been measured. Some of these values may permit an assessment of the relative contribution of strand breakage to the inactivation of simple microorganisms.