Abstract
Most in the field of ionizing radiation damage to DNA in frozen aqueous solutions agree that two major types of radical ions are formed, i.e. ·G+/·A+ and ·T−/·C−. The main evidence stems from EPR and strand break studies. Fluid solutions exposed to laser light are known to give G·+ and e−solv with low yields of single strand breaks. We have explored this contrast by photoionizing DNA solutions at 77K, in the expectation that this would prevent the formation of e−solv and hence that the results might be similar to those for high energy radiation. They are not: the results show only the formation of G·+ (or) A·+). the fate of the ejected electrons is unclear except for sodium perchlorate glasses when they react to give O·−.