The Isolation and Oharacterization of An Rna Bacteriophage

An enrichment procedure for the isolation of RNA bacteriophage is described. The method involves the inoculation of sewage samples into cultures of Escherichia coli K-12 Hfr under conditions where DNA synthesis is restricted by the addition of 5-fiuorodeoxyuridine to the culture medium. Six phage isolates were made and all of them were shown to be male-specific. One of the male-specific phage was further characterized as an RNA phage, having very similar properties to RNA phage already isolated in other parts oftha world. This RNA phage has a buoyant density of 1·42 g/cm3 in caesium chloride. and has a sedimentation coefficient of 79'5 Sin O'Ol:M Tria-HOI buffer, pH 7· 4, at 20°0.