Cell surface changes observed in MC-29 virus-infected chicken-embryo fibroblast (CEC) cultures.

By transmission and scanning electron microscopic studies of MC-29 virus-infected CEC cultures, C-type virus particles were detected in the medium of infected cultures, in infected cells and in intracellular vacuoles. Virus budding was also observed. In the scanning electron microscope (SEM) so-called blebs appeared on the surfaces of the infected cells, in a number proportional to the concentration of the virus preparation. On the basis of the size of the blebs, it could be considered that virus formation was taking place in their center. In control cells, neither viruses nor blebs were observed. This method will presumably be suitable for the titration of virus preparations.