It has been found that the neutralizing capacity of a given antiserum to the virus of Western equine encephalomyelitis varies according to the conditions under which the neutralization is carried out. By intra-abdominal test a linear relationship was noted between antiserum concentration and virus neutralized when plotted on a log-log scale. By intracerebral test there was a similar relationship when fresh or frozen antiserum was tested. A reaction occurred in vitro between such sera and virus when incubated at 37 C.
A different relationship was observed between virus and anti-serum which had fallen in neutralizing capacity as a result of standing at 4 C or of heating at 56 C one-half hour. Heating denatured the antiserum and induced a perceptible difference in the electrophoretic picture. The neutralizing capacity of sera kept at 4 C could be fully restored by addition of complement. Antibody in rabbit antiserum, fractionated by salting-out, was found only in the pseudo-globulin fraction; neutralization by this globulin could also be enhanced by complement. Antibody was found distributed throughout electrophoretically separated serum fractions, not only in the v globulin, but also in the β globulin and in the albumin.
↵1 This study was carried out under the Commission on Neurotropic Virus Diseases, Board for the Investigation and Control of Influenza and Other Epidemic Diseases in the Army, Preventive Medicine Service, Office of the Surgeon General, United States Army.
- Received September 2, 1944.
- Copyright, 1945, by The Williams & Wilkins Company
- Copyright © 1945 by The American Association of Immunologists, Inc.