﻿IMMUNITY RESEARCH. 347 



The technique in testing organ extracts for anti-tuberculin is the same, 

 except that fixed quantities of a stock preparation of tuberculin and of 

 complement are used with varying quantities of organ extract. 



The following controls must accompany every test : 



1. The organ extracts must be free from tissue particles, as these 

 alone may bind complement. 



2. The deflecting power of organ extracts alone and of tuberculin 

 alone must be determined in the test for anti-tuberculin, and that of 

 organ extract alone and of anti-tuberculin alone in the test for tuber- 

 culin. Occasionally, one of these substances exhibits a certain power 

 of deflection. 



3. The extract to be tested must be added to the sheep corpuscle-serum 

 mixture to determine whether it alone effects haemolysis. 



4. A complete parallel series must be made at the same time, using 

 nontuberculous organs from the species to which the test animal belongs. 



5. The controls usual in every hemolytic experiment must, of course, 

 be set also — that is, sheep's corpuscles and salt solution; corpuscles and 

 amboceptor ; corpuscles and complement alone. 



The haemolytic dose of the specific rabbit's serum is determined in 

 preliminary tests and likewise that of the complement serum. About 

 twice the haemolytic dose of amboceptor and the single dose of comple- 

 ment are employed in the experiment. 2 



ISTeisser and Sachs (28) state that deflection by serum and anti-serum 

 fails if the anti-serum is first boiled, and they include a control with boiled 

 anti-body in their forensic test. They also state that there is an optimum 

 amount of the anti-serum causing deflection when added to complement 

 and the suspended blood specimens. This amount is determined at a 

 preliminary test in which varying amounts of anti-serum are employed 

 with a fixed amount of complement, and a fixed amount (0.0001 cubic 

 centimeter) of the test blood preparation. At first they recommended 

 the employment of normal rabbit serum with sheep's corpuscles as the 

 haemolytic indicator, but later they advised the use of a specific serum 

 with sheep's corpuscles. 



The application of the deflection method by Wassermann and Bruck 

 (35) to the study of tuberculosis apparently sheds light upon the bac- 

 terial and anti-bacterial reactions occurring in tuberculous individuals. 

 In tuberculous organs and in the sera of animals treated with tuberculin, 

 anti-tuberculin was demonstrated, while it was absent from the sera of 

 thirteen patients at different stages of phthisis. They succeeded in de- 

 monstrating tuberculin also in the diseased organs. As the aniti-tuberculin 

 receptors are elaborated at the tuberculous focus, and as they usually 



2 For a clear description of the technique and of the controls necessary, see 

 Wassermann and Bruck, Miinchen. med. Wchnschr. (1900), p. 2396, and Morgen- 

 roth and Stertz, Virchow's Archiv. (1907), 188, p. 166. 



