Radiation-induced crosslinking of cytosine

Formation of dimers upon gamma irradiation of cytosine, 2'-deoxycytidine, and 2'-deoxycytidine-5'-monophosphate in N2O-saturated aqueous solutions was found to be a major process. Quantitative measurements revealed that more than 50% of OH adduct radicals of cytosine undergo dimerization. Derivatized dimers and monomeric products were separated and tentatively identified by combined capillary gas chromatography-mass spectrometry.