THE LYSIS OF RED BLOOD CELLS "225 



minutes at 56° C. He also showed that this inactivation concerned not the haemo- 

 lytic antibody itself but a second non-specific thermolabile factor, which caused 

 the lysis of the red cells when these had been sensitized by the specific hsemolysin. 

 This non-specific, thermolabile factor, which is present in all normal, fresh, unheated 

 sera, was named alexine by Buchner. Ii is now generally known by the name 

 complement employed by Ehrlich. 



The fundamental reactions that demonstrate the nature of the lytic reaction 

 may be briefly summarized as follows : The defibrinated or citrated blood of a 

 suitable animal, such as the sheep, is centrifuged, and the deposited red cells are 

 separated and washed several times in saline to free them from the last traces of 

 serum. The washed cells are then made into a 5 per cent, suspension in saline. 

 The serum from some convenient animal — usually a rabbit — that has received 

 repeated injections of washed sheep corpuscles and has in consequence produced 

 a specific hsemolysin to high titre, is heated at 56° C. for 30 minutes to inactivate 

 the normal complement. The fresh, unheated serum of some other animal, usually 

 the guinea-pig, is used as a source of complement. When these reagents are mixed 

 in various combinations, and the mixtures incubated at 37° C, the following results 

 are obtained : 



(1) Ked cells + Hsemolysin — > No haemolysis. 



(2) Eed cells -\- Complement — > No haemolysis. 



(3) Red cells -f Hsemolysin + Complement — >■ Complete haemolysis. 



If mixtures (1) and (2) are centrifuged, and the deposit and supernatant fluid 

 examined separately for the presence of hsemolysin and complement, the following 

 results will be noted, provided that the proportions of the reagents in the original 

 mixtures have been suitably adjusted. 



(4) Deposit from (1) + Complement — > Complete haemolysis. 



(5) Supernatant from (1) -J- Red cells -|- Complement — >■ No haemolysis. 



(6) Deposit from (2) -f- Hsemolysin — >■ No hsemolysis. 



(7) Supernatant from (2) -(- Red cells -}- Hsemolysin — >■ Complete hsemolysis. 



Reaction (4) shows that hsemolysin has combined with the red cells in (1) and 

 sensitized them to the lytic action of complement. Reaction (5) confirms this by 

 demonstrating the absence of hsemolysin from the supernatant fluid. Reaction (6) 

 shows that complement has not combined directly with the red cells in (2). 

 Reaction (7) confirms this by demonstrating the presence of complement in the 

 supernatant fluid. 



The controversy that arose between Bordet and his co-workers on the one 

 hand, and Ehrlich and his school on the other, concerned the mode of union 

 between the complement and the sensitized red cells. As already indicated, 

 Ehrlich's conception of the haemolytic antibody was that of a special type of 

 side-chain, which he referred to as a receptor of the third order, or an amboceptor. 

 He endowed this hypothetical receptor with two haptophore, or combining groups, 

 one of which united with the red cell, and was named by him the cytophilic 

 group, while the other united with the complement, and was named the com- 

 plementophilic group. Ehrlich's conception of the structure and mode of action 

 of an amboceptor may be represented as in Fig. 40a. In the diagram, R.C. repre- 

 sents the red cell, and R one of its receptors ; A the amboceptor, or hsemolysin, 

 attached to the receptor of the red cell by its cytophilic haptophore group Cy, 

 and to the complement by its complementophilic haptophore group Cm ; C repre- 



P.B. I 



