Printed in Great Britain 383 The Fluorescent Staining of Bacteriophage Nucleic Acids

Abstract

The staining of viral nucleic acids with acridine orange and their subsequent exaniination under the fluorescence microscope permits the determination of the type and strandedness. Since the existing procedures are complicated, modifications have been devised which simplify them and avoid the use of the fluorescence microscope, an ordinary ultraviolet lamp being substituted. Also, it has been found that certain post-staining treat-ments cause colour changes which are related to the strandedness and type o i nucleic acid and hence are valuable confirmations of the normally used nuclease sensitivity tests. The new procedures were tested for a wide range of specimens including double-stranded ribonucleic acid, but emphasis has been placed on the identification of bacteriophage nucleic acids