Abstract
Virions of human cytomegalovirus were shown to contain two discrete membranes. An outer, loose fitting, membrane was sensitive to osmotic shock and could be partially removed by diluting buffered preparations of virions with water. Purified virions were shown, by SDS-polyacrylamide gel electrophoresis of virion membranes labelled by carbohydrate-specific procedures, to contain five glycoproteins with molecular weights of 52, 67, 95, 130 and 250, all x 103. Digestion of virions with endoglycosidases revealed that there were structural differences between the carbohydrate portions of the glycoproteins. All five glycoproteins were recognized by antibodies present in pools of human convalescent sera.