Propagation of B-Virus in Tissue Cultures.∗

Summary 1. A B-virus strain isolated from “normal” monkey kidney was propagated in cultures of monkey kidney and chick embryo tissues. 2. The B-virus strain studied was relatively stable in tissue culture medium when stored at 4°C. Freezing seemed to destroy some activity, but there was no further loss demonstrable on storage at −20°C and −72°C. 3. Approximately 27% of 513 rhesus monkey sera showed neutralizing activity for the isolated B-virus strain.