Immunofluorescence with respiratory syncytial virus

The growth of respiratory syncytial (RS) virus in tissue cultures of HEp-2 cells at a low multiplicity of infection has been studied by means of several staining procedures including immunofluorescence, as well as by serial infectivity titrations.Specific fluorescent staining was first noted 10 hours after infection and was restricted entirely to the cytoplasm throughout the growth cycle.A significant increase in the amount of infectious virus present in the system was first detected 10 hours after inoculation, and peak values were achieved after 48 hours.The pattern of development of RS antigen has been compared with that of other medium-sized ether-sensitive agents and possible taxonomic implications are discussed.