Use of the initial portion of the melting curve for determining locally denatured sites in DNA radiation damage

A simple approach is proposed to determine locally denatured sites and stability characteristics of secondary DNA structure. The method is based on the analysis of the initial part of melting curve and the determination of changes in the optical density of DNA after heating up to a fixed temperature. The potentiality of the approach is illustrated by the experiments with DNA containing defects in the secondary structure caused by gamma-irradiation in vitro. The sensitivity of the method is less than 0.2 Gy.