Chromatographic Studies on the Radiolysis of DNA in Aqueous Solution

Summary

Radiation-induced degradation of double-stranded DNA from calf thymus in aqueous solution with sodium phosphate was studied by conventional gel chromatography and by high-performance liquid–gel permeation chromatography. Comparison of the data after radiolysis of aqueous solutions of DNA under anaerobic and aerobic conditions indicates that double-strand breakage is not enhanced by oxygen. An increase of ionic strength impedes the break-down of the DNA molecules, so that loss of DNA can only be observed at doses above 100 Gy. Only reactions of OH·-radicals contribute to the fragmentation of DNA, while the presence of hydrated electrons, H·-or formate radicals does not lead to a loss of highly polymerized DNA up to doses of 1500 Gy. High-performance liquid-chromatography proved to be an excellent method of studying the degradation of macromolecules as a function of dose.

• DNA
• oxygen effect
• gel chromatography