Ribonucleic Acid Yield Research Articles

The isolation and composition of the nucleic acids of Aerobacter aerogenes.

SUMMARY: The nucleic acids were isolated from Aerobacter aerogenes by extraction of mechanically disintegrated organisms with 0·14 m-sodium chloride at pH 7·5. Upon subsequent isolation, about 80 % of the deoxyribonucleic acid (DNA) originally contained in the organisms was obtained, but only about 50% of the ribonucleic acid (RNA). The loss of RNA was mainly due to enzymic degradation. By extraction of A. aerogenes with 1 % sodium cholate at 60°, enzymic degradation was virtually eliminated and a good yield of both DNA and RNA obtained. They were relatively undegraded and both showed evidence of the presence of hydrogen bonds. The amounts of the purine and pyrimidine bases in both types of nucleic acid were determined. The DNA and RNA from the normal streptomycin-sensitive strain of A. aerogenes differed significantly in base composition from the corresponding nucleic acids from a strain which had been trained to grow in 5 % (w/v) streptomycin.

Isolation of nucleic acids from Micrococcus lysodeikticus.

WE have found a simple method for the preparation of a mixture of ribonucleic acid and deoxyribonucleic acid and the preparation of purified deoxyribonucleic acid in a highly polymerized state from cells of M. lysodeikticus. In arriving at the techniques, we have taken advantage of the fact that above pH 8.0 the activity of the ribonuclease system in M. lysodeikticus is negligible. Moreover, in the absence of orthophosphate, polynucleotide phosphorylase (polyase) is inactive toward ribonucleic acid. Therefore, for maximum yields of ribonucleic acid the lysis of the cells was carried out at pH 8.5. To destroy the ribonucleic acid selectively orthophosphate was added1. This communication presents some of the preliminary results.