386 HEMOLYSINS 



ment by heating the serum to 56 C. To this he added some sheep's 

 corpuscles, and allowed the mixture to stand for a short time at room 

 temperature, after which it was centrifuged and the supernatant fluid 

 pipeted off in another test-tube. No hemolysis had occurred, and the 

 corpuscles were to all appearances unaltered, but it was now found that 

 if a small amount of normal goat serum, as complement, was added to 

 the corpuscles and the mixture placed in the incubator, hemolysis oc- 

 curred. By adding sheep's corpuscles and normal goat serum (comple- 

 ment) to the supernatant fluid that had been removed to a separate test- 

 tube, hemolysis did not occur. This experiment indicated, therefore, 

 that the red blood-corpuscles had combined with all the antibody. 

 That the action was specific was shown by the fact that the corpuscles 

 of other animals, such as rabbits or goats, for example, exerted no com- 

 bining power when used instead of the sheep's cells. The union between 



cell and antibody was considered as 

 being in the nature of 'a chemical com- 

 bination and quite firm, as repeated 



6 -V.fi 1 washing of the cells with normal salt 



FIG. 105.-THEOBETIC STRUCTURE S luti n dW DOt break '* U P' 

 OF A HEMOLYTIC AMBOCEPTOR Having shown that the antibody 



(HEMOLYSIN). had & combinmg a ffi n i ty f or the cells, 



A, Amboceptor; C, comple- 

 ment; r, receptor of the corpuscle; it was important to solve the question 



bocep?orf\ 0r e , ?omJ>lempSle" of the relation of alexin or complement 

 group of the amboceptor. to the process. In other words, does 



this substance unite directly with the 

 cell or does it unite with the antibody and thus indirectly with the cell? 



Ehrlich and Morgenroth studied this by means of a similar experi- 

 ment. Sheep's corpuscles were mixed with normal goat serum (com- 

 plement), and after a time the mixture was centrifuged and the two por- 

 tions tested separately. To the corpuscles heated immune serum was 

 added, but hemolysis did not result. To the supernatant fluid cor- 

 puscles and heated immune serum were added and hemolysis occurred. 

 This indicated that the alexin or complement did not unite with the 

 corpuscles, as did the antibody in the first experiment, but remained 

 free in the supernatant fluid. 



By mixing corpuscles, immune serum, and complement and keeping 

 the mixture at 0-3 C. for several hours, hemolysis did not take place. 

 By centrifuging the mixture and separating the supernatant fluid from 

 the corpuscles, a similar test showed that the red cells had combined 

 with all the antibody, but had left the alexin practically undisturbed. 



