[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
[Skip to Content Landing]
October 16, 1943


Author Affiliations


From the Department of Bacteriology, Columbia University College of Physicians and Surgeons.

JAMA. 1943;123(7):399-402. doi:10.1001/jama.1943.02840420011005

Following isolation and identification of the murine strain of SK poliomyelitis virus1 in this laboratory, subsequent work has been concerned with purification of the infectious agent. By using physical and chemical methods of extraction and concentration, highly potent virus preparations were obtained from infected mouse brains. These preparations possessed an appreciable degree of physical homogeneity, as determined by ultracentrifugation, and reacted in precipitin tests with specific antiviral serums.2 The purified material seemed to offer a good opportunity to gather additional information on the morphologic characteristics of the infectious agent by means of further study with the electron microscope. For the same purpose there were also available tissue culture preparations of SK murine virus. The latter were examined in the unpurified state. sion of the Research Laboratories of the American Cyanamid Company at Stamford, Conn. The instrument employed was the commercial RCA model which permitted primary magnifications between