Investigation of local radiation injuries in DNA by the method of thermal separation of spirals

By the method of thermal separation of strands a study was made of the local injuries in the DNA macromolecule caused by x-ray and ultraviolet irradiation. By analysis of the degradation kinetics and flexibility of the initial and final products it was shown that A-irradiation causes no cross linking preventing the separation of DNA strands; at the same time irradiation leads to the appearance of solitar breaks in polynucleotide chains. Finally, in ultraviolet irradiation thermostable cross-linking is formed, preventing the separation of the two-stranded structure.