144 BACTERIOLYSINS AND HEMOLYSINS 



Hemolysins. 



An animal that is injected with the red blood cells of a different species 

 develops in its serum antibodies which are biologically analogous to 

 bacteriolysins and differ from them only in that they cause disintegration 

 of erythrocytes instead of bacteria. These antibodies are therefore 

 called hemolysins, or to be more precise immune-hemolysins, since they 

 arise through a process of immunization. The breaking up of the red 

 blood corpuscle, hemolysis, is recognized by the naked eye. The hemo- 

 globin passes from the erythrocytes into the surrounding fluid (serum or 

 physiological salt solution) and colors it red. The previously opaque 

 blood lakes and becomes transparent. Immune-hemolysins like bac- 

 teriolysins belong to the class of amboceptors. They are relatively ther- 

 mostabile in that they withstand a temperature of from 56 to 58 C. 

 without being injured; they require complement for the develop- 

 ment of their hemolytic action. Furthermore, immune-hemolysins, like 

 all amboceptors, are specific, i.e., the serum of a rabbit immunized 

 against horse's blood can dissolve only the blood of a horse and not that 

 of a hen or cow. On the other hand, group reactions occur here also; for 

 instance the immune-hemolysin produced in a rabbit against horse's 

 blood is likewise active against donkey's blood. 



Just as various antitoxins, agglutinins, precipitins and bac- 



Normal teriolysins can be found in normal serum, so also can normal 



Hemolysin. hemolysins of amboceptor structure be discovered in the 



blood of many animals. 



While normal hemolysins come into play in only a few reactions, as in 

 several modifications of the Wassermann test, the significance of immune- 

 hemolysins is extraordinarily great. These antibodies, discovered by 

 Bordet, and independently by von Dungern and Landsteiner, were care- 

 fully studied by Ehrlich and Morgenroth and many others. Such re- 

 searches have, first of all, greatly advanced the subject of immunity in its 

 theoretical aspects, in that they have created the possibility for the dis- 

 covery in minute detail the finer relationship which has explained some of 

 the phenomena occurring in bacteriolysis. Furthermore, the studies of 

 hemolysins led to the discovery of the complement fixation method, a 

 procedure of exceptional practical value. 



As far as the technique for obtaining immune-hemolysins is 



Production concerned, the rules which hold for every process of immu- 



ofHemo- nization are naturally to be followed here also. It is not 



lytic Sera, possible, however, to immunize every kind of animal against 



every type of red blood corpuscle. Rabbits, goats, horses 

 and chickens are the ones which are best adapted to supply hemolytic sera. 

 An animal produces a better hemolysin the remoter its relationship to the 



