Purification and serology of the W strain of cucumber mosaic virus

During studies on the purification of cucumber mosaic virus (strain W) it was found that preparations were most infective and stable when made from tobacco leaves (10–12 days after inoculation) homogenized in phosphate buffer containing EDTA and thioglycollic acid and clarified with diethyl ether. The preparations were further purified by centrifugation in sucrose density gradients containing EDTA at pH 9.0 and were then stable at 2 °C for > 100 days. When mounted in neutralized ammonium molybdate they were shown to consist of predominantly intact particles. In tube and ring precipitin tests and in agar gel-diffusion tests, specific precipitation with homologous antiserum occurred only in media containing alkaline adjusted solutions (ammonium molybdate and dipotassium hydrogen phosphate).