346 



Scientific Proceedings (123). 



ments of Ford and Halsey 1 as well as those of Bennett and Schmidt 2 

 nevertheless indicate that it is also possible to obtain a hemolytic 

 sensitizer by immunization with the water-soluble portion of red 

 cells. Moreover, the findings of Balls and Korns that the filtrate 

 obtained by passing a solution of hemolyzed red cells through a 

 porcelain filter does not bind hemolytic sensitizer do not appear 

 to us as conclusive evidence that the antigen is contained wholly 

 in the stroma. It is a well-known fact that the first portion of the 

 filtrate obtained on passing a solution of proteins such as serum 

 through a porcelain filter invariably shows a loss of protein and 

 that the latter portions of the filtrate are relatively richer in pro- 

 tein than the first. The experiments of Muir 3 with the water- 

 soluble portion of red cells clearly indicate that the first portion 

 of the filtrate is unable to bind sensitizer while the latter portions 

 can unite with increasing amounts. 



Vedder 4 dissolved the stroma obtained from human red cells 

 in dilute alkali, neutralized the solution with acetic acid and fil- 

 tered off the protein precipitate. Rabbits were immunized with 

 both this fraction and the protein contained in the filtrate. The 

 latter, which Vedder believes to be an albumin, gave rise to the 

 hemolytic sensitizer for human cells while no antibodies were ob- 

 tained by immunization with the acetic acid precipitate. 



Bennett and Schmidt 2 carried out experiments with the C0 2 - 

 globulin isolated from a solution of the constituents of ox red cells 

 after removal of stroma by centrifuging and filtration. Rabbits 

 were immunized with this protein and a specific sensitizer and an 

 agglutinin for the homologous red cells were obtained. Since the 

 experiments were carried out with the red cells of only one species 

 and since the experiments of Vedder indicate that possibly in the 

 red cells of other species a protein other than the CCVglobulin 

 may be the antigen concerned in the production of hemolysis, it 

 appeared to us desirable to carry out experiments with the globu- 

 lins obtained from the red cells of several other species. 



Antigens were prepared from the red cells of the sheep, the 

 pig and man in accordance with the method described by Bennett 



1 Ford, W. W., and Halsey, J. T., Jour, of Medical Research, 1904, xi, 403. 

 1 Bennett, C B., and Schmidt, C L. A., Jour, of Immunology, 1919, iv, 29. 

 ■ Muir, R., "Studies on Immunity," London, 1909, p. 129. 

 * Vedder, E. B., Jour, of Immunology, 1919, iv, 141. 



