Alkali-labile Sites and Post-irradiation Effects in Gamma-irradiated Biologically Active Double-stranded DNA in Aqueous Solution

Abstract

SummaryGamma-irradiation of double-stranded RF-DNA of bacteriophage ϕX174 in aqueous solution in the presence of oxygen produces at least one type of alkalilabile site. It is lethal and gives rise to breaks by alkali and is identical with the damage which becomes manifest by post-irradiation heat treatment. The effect of alkali is dependent on temperature. Furthermore, the excision repair system is not involved in eliminating lethal nucleotide damage in RFI-DNA.