XII 



FIXATION OF COMPLEMENT 



PRINCIPLES OF THE REACTION— BORDET-GENGOU PHE- 

 NOMENON— WASSERMANN-NEISSER-BRUCK MODIFICA- 

 TION— TECHNIC OF THE WASSERMANN REACTION IN 

 THE DIAGNOSIS OF SYPHILIS— MODIFICATIONS OF THE 

 WASSERMANN REACTION— HECHT-WEINBERG MODIFI- 

 CATION—CLINICAL APPLICATION OF THE WASSER- 

 MANN REACTION— EFFECTS OF TREATMENT ON THE 

 WASSERMANN REACTION 



In the foregoing chapter we have seen that bac- 

 teriolysis, cytolysis, and hsemolysis take place by 

 means of a specific substance known as amboceptor, 

 and a non-specific substance called complement. This 

 imion of antigen, amboceptor, and complement is 

 spoken of as fixation or ahsoi'ption of complement. 

 The exact nature of the reaction is not known. In 

 order that the complement-fixation reaction be under- 

 stood in its application to specific diagnosis, it is neces- 

 sary to explain first in some detail the process of 

 hgemolysis. When red blood-corpuscles remain in sus- 

 pension in a fluid, the fluid has an opaque red color. 

 If haemolysis occurs, the haemoglobin leaves the cor- 

 puscles, the fluid becomes transparent, and has a deep 

 red color. If no haemolysis occurs, the corpuscles 

 gradually fall to the bottom of the tube, leaving clear, 



colorless fluid above. Haemolysis can occur in a non- 

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