376 Use of Purified Antigen of Besredka [April-July. 



Having thus proved that the lipin fraction of the tuberculin has 

 no antigenic value in the complement deviation test of tuberculosis, 

 and therefore can be removed and thus the antigen purified, we 

 sought to determine further what fraction, if any, of the protein 

 part of the tubercuhn is responsible for its antigenic properties. 

 Tubercuhn contains protein materials f rom egg-white and egg-yolk, 

 also Proteose, peptone, amino acids and other soluble protein de- 

 rivatives in the beef broth, as well as different products resulting 

 from the cleavage of said substances in the nutrition of tubercle 

 bacilH. The problem of isolating each protein and protein deriv- 

 ative, and testing for any corresponding antigenic values, there- 

 fore, is a very difficult one, but we are endeavoring to study it fol- 

 lowing the suggestions of Professor Gies. 



