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PRACTICAL METHODS IN IMMUNITY 



Even in a small laboratory there are no particular difficulties in the way of hav- 

 ing on hand rabbits immunized against typhoid, paratyphoid, Malta fever, acid- 

 producing and nonacid-producing strains of dysentery, cholera, etc. Just as we 

 inject men with vaccines prepared from various bacteria in opsonic therapy, so we 

 inject animals to produce sera for diagnosis. We may use either a bouillon culture 

 or the growth on agar slants taken up with salt solution as the inoculating material. 

 This is heated for one hour at 60 C. to kill the bacteria. Where we desire to produce 

 a serum which will disintegrate red blood cells (haemolytic serum), we inject about 

 5 c.c. of the washed red cells of the animal for which we wish to produce a specific 



FIG. 47. i, Red cells -f- normal serum. No amboceptor. No haemolysis. A, 

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

 amboceptor. Haemolysis. C, Complement; D, amboceptor; E, haemolyzed red 

 cell. 3, Red cells + immune serum heated to 56 C. Inactivated. Complement 

 destroyed. No haemolysis. F, Destroyed complement; G, amboceptor; H, red 

 cells. 4, Red cells + heated immune serum + fresh serum. (Activated by con- 

 tained complement.) Haemolysis. I, Destroyed complement; J, fresh complement; 

 K, amboceptor; L, haemolysed red cell. 5, Diagram showing antitoxin production. 

 a, Toxin molecule; b, antitoxin molecule; c, neutralization of toxin by antitoxin. 

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



serum. For details see method of preparing haemolytic amboceptor serum under 

 Noguchi's mcdification of Wassermann test. For preparing a serum for the bio- 

 logical blood test we inject the rabbit with human serum in quantities of about 

 5 c.c. every fifth day. About one week after the last injection the antiserum ob- 

 tained from the injected rabbit should be strong enough for one-tenth of a c.c. to 

 produce turbidity when added to i c.c. of a i-iooo dilution of human serum in salt 

 solution. Various controls are necessary when used in medico-legal work. 



