Several attempts have been made by various investigators to obtain a specific antigen for complement fixation in poliomyelitis, so far without success. We have obtained a specific antigen by digesting poliomyelitic virus with trypsin. A 5% suspension of brain and cord of monkeys that have died of poliomyelitis is filtered through a Berkefeld or Heim filter. sterile water being used as the menstruum. The trypsin is added in proportion of 1 : 50 and permitted to act at room temperature for three

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... ours; 0.4% tricresol is then added to stop further action by the trypsin.' The poliomyelitis antigens were diluted 1-5, the spinal fluid was used in 10 times the amount of the serum. The tubes were incubated as a rule for 2 hours in the water bath at 37 C. Earlier in the work, the antigen was used in less than one-fourth and later less than one-half of the anticomplementary dose. It is not inclined to be anticomplementary and was tested with each reagent alone, and these controls gave no hemolysis. The bacterial antigens used as controls in our study of complement fixation in poliomyelitis were prepared by the methods employed by Miss M. A. Wilson in this laboratory, who made all the tests. A saline emulsion of the dried organisms is made and the standard dose determined by titration with a homologous serum of known titer. The standard dose of each antigen contains 2 fixation units and one-fourth, or less, of the anticomplementary dose. The meningococcus tests are held for 30 minutes in the water bath at 37 C. The tuberculosis and streptococcus tests are held for 2 hours in the water bath at 37 C. The antigen for the Wassermann tests was a cholesterinized alcoholic extract of guinea-pig-heart or ox-heart, made by Dr. Hadsopulos of the Wassermann department of Bellevue Hospital. The tubes were kept 1 hour in the water bath at 37 C. In all of the tests 2 units of complement and 2 units of amboceptor were used, the cells having been sensitized with the amboceptor before they were added; 0.1 c.c. of a 5% suspension of sheep's corpuscles was used for indicator of the reaction of fixation.