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. 



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 bacteriofysins. 



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. gr., 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 

 preparing the emulsion. This difficulty may be reduced to a minimum 

 by thoroughly washing the organ or tissue prior to preparing an emulsion 

 for injection. 



The following method, after Pearce, illustrates the mode of preparing 

 a nephrotoxic serum by immunizing rabbits with dog kidney. 



1. Anesthetize a dog with ether, open the abdomen, wash the blood 

 out of the kidneys by inserting a cannula high up in the abdominal aorta, 

 and flushing with from six to ten liters of salt solution; open the vena 

 cava. 



