Abstract
1. Studies concerning incorporation of the radioactive label into nucleic acids after feeding [8-14C]adenosine-5′-carboxylic acid ethyl ester, were conducted with the mouse and dog. The nucleic acids were isolated, separated on methylated albumin Kieselguhr columns, and their base compositions determined using ion exchange resins.
2. All isolated nucleic acids (s-RNA, DNA, r-RNA) were labelled with 14C in both mouse and dog. Only the purine bases, adenine and guanine, carried the label, in the proportion of 3 : 1. Besides these two, no other labelled bases were found.
3. It was concluded that the adenine moiety of [8-14C]adenosine-5′-carboxylic acid was split off and reutilized for nucleic acid syntheses.