%0 Journal Article %A Weiss, R. A. %T Interference and Neutralization Studies with Bryan Strain Rous Sarcoma Virus Synthesized in the Absence of Helper Virus %D 1969 %J Journal of General Virology, %V 5 %N 4 %P 529-539 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-5-4-529 %I Microbiology Society, %X SUMMARY The relationship of RSVβ(O) to other avian tumour viruses was studied by virus interference and serological cross neutralization. Viruses of subgroup B interfere with RSVβ(O) on chicken cells but not on quail cells. Viruses of sub-groups A and C enhance the focus forming efficiency of RSVβ(O). Antisera to RSVβ(O) and avian tumour viruses of sub-group A, B and C do not cross-react, but serological cross-reaction was found between RSVβ(O) and sub-group D. The ability of RSV(O) and L-R cells to stimulate anti-viral antibodies has been investigated. No helper virus in RSVβ(O) stocks was demonstrable by interference assays. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-5-4-529