Morphology of Type II Poliomyelitis Virus (MEF1) as Determined by Electron Microscopy.

Abstract
The particles of the MEF-1 poliomyelitis virus, grown in monkey-kidney tissue culture, and subsequently purified by chemical and physical means, are spherical in shape and highly uniform in diam.. The diam. of individual particles, prepared by normal air-drying from a 0.1[image] ammonium acetate suspension, is 31 m[mu]. The diam. of particles packed in a crystalline array, or frozen dried from a 0.1 [image] ammonium bicarbonate suspension, is 27 m[mu]. It is believed that the latter diam. is the more significant and reliable figure.