Abstract
Some aspects of the adsorption and release of Newcastle disease and Sendai viruses were studied in excised pieces of allantois of uniform size. About 40% of any saturating dose of either virus was adsorbed. The % adsorption was not influenced by treatment with neuraminidase. One-step growth curves indicated that the release process for both viruses was linear. The rate of release and the burst size were influenced by the composition of the medium used for maintaining the allantoic cells. Increases in the multiplicity of infection decreased the length of the latent period. Treatment of allantoic cells with suitable doses of actinomycin D or ultraviolet irradiation also affected the length of the latent period. These agents may increase the susceptibility of cells to infection by affecting DNA-directed mechanisms concerned in the control of nucleic acid synthesis.