ACTIVATION OF IMMUNE SERA. 



I2 3 



of a nonimmunized animal which contains the complement, but no 

 specific immune body (amboceptor) to the heated serum. This is 

 termed "activating," and a serum so treated is said to be "activated." 

 When an immune serum has been heated to 56 C., it is said to have 

 been "inactivated". 



FIG. 47. i, Red cells + normal serum. No amboceptor. Nohemolysis. A. com- 

 plement; B, normal red cell. 2. Red cells + immune serum. Complement and 

 amboceptor. Hemolysis. C, complement; D, amboceptor; E, hemolyzed red cell. 



3. Red cells + immune serum heated to 56 C. Inactivated. Complement de- 

 strojed. No hemolysis, F, destroyed complement; G, amboceptor; H, red cells. 



4. Red cells + heated immune serum + fresh serum. (Activated by contained 

 complement). Hemolysis I, destroyed complement; J, fresh complement ; K, am- 

 boceptor; L, hemolyzed red cell. 5, Diagram showing antitoxin production. 

 a, toxin molecule; &, antitoxin molecule; c, neutralization of toxin by antitoxin. 

 6. Diagram showing bacteriolysin. d, complement; e, amboceptor; /, bacillus. 



When we allow a mixture of bacteria or cells to remain in contact 

 with their specific immune serum which has been inactivated, the 

 amboceptors attach themselves to the bacteria or cells, so that now, upon 

 adding normal serum (complement), these bacteria or cells are so pre- 



