Immunoferritin studies on the multiplication of Sindbis virus in chick embryo fibroblasts

Replication of Sindbis virus chick embryo fibroblasts was studied by means of the immunoferritin technique. Virus specific antigens, diffusely distributed in the cytoplasm, were observed at first 3 hours p.i. At the same time in ohter cells ferritin particles in linear arrangement occured at the surface of vesicles. At these places heavily labelled nucleocapsids were observed later on. This means, that the surface of vesicles is a site of assembly of nucleocapsids. Maturation of virus takes place at the cell surface as well as at the vesicles by budding. In early stages of replication maturation at the membrane prevalis.