Competition radioimmunoassay for mason-pfizer monkey virus: comparison with recent isolates.

The major core protein of Mason-Pfizer monkey virus was purified by DEAE ion exchange column chromatography and shown to be 27,000 daltons (p27). Following the characterization of monospecific antisera prepared against p27, a radioimmunoassay was developed with these reagents and competition experiments were done with come of the recent M-PMY-like isolates as well as with other oncornaviruses. Results suggest that three of the viruses tested, AO, X-381 and FTP-1, are similar to M-PMV while J-96 virus is related, but not identical, to M-PMV. It is also shown that competition RIA can be used successfully to detect the presence of viral proteins in tissue homogenates and cell extracts.