The Incorporation of Isotopic Phosphate in the Mononucleotides of Liver Nucleic Acids¹

Incorporation of radioactive phosphate into the nucleic acids of brain slices

“…For purine nucleotides, adenylic acid was always found to be more active than guanylic acid, and for the pyrimidine nucleotides, uridylic acid was more active than cytidylic acid. These findings are similar to those reported by Volkin & Carter (1951) and Davidson & Smellie (1952 b) for the specific activities of the nucleotides of the PNA of liver tissue after the administration of 32p in vivo.…”

“…Vol. 55 32p AND NUCLEIC ACIDS OF BRAIN SLICES 199 vivo, the a and b isomers of adenylic and guanylic acid were shown to be metabolically indistinguishable (Marrian et al 1951, for 14Cand 1IN-labelled adenine; Volkin & Carter, 1951, for 32p). The experiments reported above indicate that 32psi readily incorporated into the PNA of brain slices and that the incorporation is dependent upon the metabolism of the slice.…”