PRODUCTION OF CYTOTOXINS 73 



This method is especially serviceable in preparing antihuman 

 amboceptor. Whenever possible, blood should be collected aseptically, 

 and the corpuscles washed just before the injections are given. Pla- 

 cental blood is likely to be infected and hemolyzed, and frequently 

 yields unsatisfactory results. In preparing the antihuman amboceptor 

 several rabbits should be immunized at the same time, the doses being: 



First dose: 5 c.c. of the washed corpuscles. 



Second dose: 8 c.c. of the washed corpuscles. 



Third dose: 12 c.c. of the washed corpuscles. 



Fourth dose: 15 c.c. of the washed corpuscles. 



Fifth dose : 20 c.c. of the washed corpuscles. 



A combined intravenous-intraperitoneal series of injections is fre- 

 quently of service in producing a highly potent antihuman hemolytic 

 serum. Three intravenous injections of 4 c.c. each of washed cells 

 diluted with 6 c.c. of sterile salt solution are given every five days; sub- 

 sequent injections are made by giving 1 c.c. of corpuscles intraperito- 

 neally, followed one hour later by 4 c.c. intravenously. A series of three 

 or four of these combined injections are made at intervals of five days, 

 the animals being tested at frequent intervals to determine the hemolytic 

 strength of the serum. 



PRODUCTION OF CYTOTOXINS 



The term "cytotoxins" is usually applied to cell toxins other than 

 hemolysins, such as nephrotoxins, spermatotoxins, etc., and although 

 "lysin" is frequently used, the term " toxin" is better, being descriptive 

 of the changes produced by all cell toxins except the hemolysins and 

 the bacteriolysins. 



Cytotoxic serums can be made theoretically for any cell, but only 

 the hemolysins possess much practical value. The cytotoxins are 

 prepared with some difficulty by injecting emulsions of cells from one 

 animal into another. Immunization should always be conducted by 

 means of intraperitoneal or subcutaneous injection. 



For the purpose of studying the action of cytotoxic serum, nephro- 

 toxic serum is preferably to be used, as the effects, e. g., the production 

 of albuminuria, may be observed. A series of two or three animals 

 should be carried along at the same time, as many die after the third 

 injection. So far as possible an aseptic technic should be carried out. 



Practically all cytotoxic serums are hemolytic partly because of the 

 great difficulty of removing all traces of blood from the organ used in 



