Degradation of Dry Deoxyribonucleic Acid by Polonium Alpha-Particles

Publisher Website
Google Scholar
Abstract
DNA films, ten microns thick, were irradiated and the physico-chemical properties of the DNA studied. Measurements of molecular weight, radius of gyration and intrinsic viscosity indicate that scission of the twin helix (double break) occurs every time an [alpha]-particle traverses a DNA molecule. The efficiency of this scission is 650 ev per double break and it is not affected by oxygen or water (up to 80 gms H2O 100 gms DNA). The [sigma] rays associated with the [alpha]-particle track produce breaks in one strand only of the twin helix (single break) together with a reactive center which is capable of cross-linking. Oxygen prevents crosslinking by combining with the active centers but even in vacuo the ratio of cross links to double breaks never exceeds 0.5 and insoluble gels are not formed.

This publication has 2 references indexed in Scilit: