Abstract
Double stranded RNAs obtained from plants infected with alfalfa mosaic virus have been studied by electron microscopy using the Kleinschmidt technique. Two characteristic lengths were obtained. A change of length was observed when the two strands were separated with dimethylsulphoxide. This corresponded to a change of configuration from the A form in double-stranded RNA to the B form in single-stranded RNA.
Using dimethylsulphoxide it was possible to visualize single-stranded RNA molecules as elongated filaments.
The electron microscopic results are compared with reported mol. wt values for the different RNAs present in alfalfa mosaic virus.