[Occurrence of viral particles of avian sarcoma viruses in sarcoma tissue]

An electron-microscopic examination was performed of chicken fibrosarcoma caused by avian sarcoma virus (ASV), strain B 77, to investigate virus budding and release through the cytoplasmic membrane. The virus particles of type C- were 90-100 nm in size, the electron-optically denser nucleoids being clearly differentiated from the outer membrane.