Reactive DNA. 2. Thioguanine used as a peg site for direct and specific introduction of biologically useful functional groups

An efficient method is described for one-step and specific introduction onto thioguanine in DNA of a variety of biologically useful functional groups, including carboxymethyl, hydroxyethyl, aminoethyl groups and fluorescent tag. Reaction mechanisms were examined. The method could provide new tools for biochemical studies, such as DNA repair and sister chromatid exchange, and the method may be also applicable to RNA.