Use of polyethylene glycol and fluorocarbon for the purification of avian encephalomyelitis virus.

A simple method is described for isolating avian encephalomyelitis virus (AEV) from a bulk amount of proteins and lipids in a homogenate of infected whole chicken embryos. More than 90% of the virus in the homogenate was precipitated by 4% polyethylene glycol (PEG), and the precipitate was free of approximately 90% of the total nonviral protein. When the homogenate was extracted with fluorocarbon, the aqueous fraction retained the full virus infectivity and about 70% of the protein but was free from most lipid materials. A two-step procedure (precipitation of the homogenate by 4% PEG, followed by extraction of the precipitate by fluorocarbon) gave a 50-fold purification of AEV over the original homogenate. The procedure is simple, rapid, and effective in removing nonviral proteins and lipids from host tissues. It is useful as an initial treatment of embryonic materials for the purification of AEV.