Changes in Ultra-Violet Absorption Spectra of Deoxyribonucleic Acid by Treatment with Bromine

Abstract

IN 1947, a procedure was developed¹ for the determination of pyrimidine nucleoside in which bromination and prolonged acid hydrolysis precede the performance of Bial reaction. More recently, it was also shown that marked changes in ultra-violet absorption spectra, particularly disappearance of selective absorption of cytosine, uracil and their nucleosides, occurred before and after the bromination of the compounds². While studying the effects of bromine on the chemical nature of nucleic acids, we have also found that the maximal absorption of deoxyribonucleic acid shows a decrease with increasing bromination period. In further experiments, it has also been demonstrated that acid hydrolysis of brominated deoxyribonucleic acid results in a loss of selective absorption without significant loss of phosphorus.