Nucleotide clusters in deoxyribonucleic acids. II. Investigation of methods for isolation of pyrimidine oligonucleotides

Abstract

Investigation of the degradation of DNA by H₂SO₄ under conditions designed to release pyrimidine 3′,5′ terminally phosphorylated oligonucleotides has revealed non-nucleotide products. Their presence detracts from the usefulness of this method for the quantitative analysis of the frequency distribution of pyrimidine oligonucleotides. An explanation of the mechanism of degradation of DNA by H₂SO₄ is presented. Such extraneous products are not present in formic acid – diphenylamine hydrolysates of DNA. A slight modification of the formic acid – diphenylamine method of hydrolysis, fractionation of the hydrolysate on a DEAE-cellulose column, and the use of a simple spectrophotometric method of analysis have made possible a rapid system of investigation of pyrimidine oligonucleotide clusters in DNA.