Avian encephalomyelitis virus-infected chick embryo homogenate
was precipitated with polyethyleneglycol 6000 (PEG), extracted
with fluorocarbon, concentrated by ultrafiltration, and purified by
isopycnic gradient centrifugation. The physical and chemical properties
of the purified virus were studied. The examination of purified
avian encephalomyelitis virus (AEV) with electron microscopy using
negative stain revealed virus particles which were icosahedral in
shape, lacked an envelope, and had a mean diameter of 26 ± 3 nm. It
was suggested that the viral capsid was composed of 12 capsomers located
at the vertices of an icosahedron. The virus was tentatively
given a triangulation number of one, and included in the icosahedral
class P = 1. The sedimentation coefficient (S₂₀, w) of AEV was determined
to be 148 ± 3 S. The bouyant density of the virus in CsC1 was
determined to be 1.31 to 1.32 g/ml by infectivity assay following isopycnic
gradient centrifugation. The infectivity titer of the virus
was reduced by 1.2 log₁₀ after heating at 56 °C for one hour. The virus was stabilized to the effect of heat by 1 M MgCl₂ The virus was
resistant to treatment with chloroform and trypsin. Attempts to discern
the type of nucleic acid in the virus genome were inconclusive