COMPLEMENT FIXATION IN SYPHILIS 425 



Bruek suggested this modification of the original Bordet-Gengou 

 technique for use in bacterial complement fixation, Schaudinn and 

 Hoffmann discovered Treponema pallidum, the cause of syphilis. 

 It occurred to Wassermann, Neisser and Bruck that complement 

 fixation might be used in the diagnasis of syphilis if a suspension 

 of Treponema pallidum could be o])tained for use as an antigen. 

 Since the organism could not be cultivated at the time, it was 

 finally decided to make a saline extract of syphilitic tissues rich in 

 spirochetes. The first work was done on the blood of apes in which 

 syphilis had been produced experimentally. Wassermann, Neisser 

 and Bruck ]irepared what tliey regarded as a specific Treponema 

 pallidum antigen by making a saline extract of a syphilitic fetal 

 liver rich in spirochetes. The technique employed was essentially 

 the Wassermann-Bruck modification of the Bordet-Gengou bac- 

 terial complement fixation technique except for the method of 

 antigen preparation and the controls which this modification made 

 necessary. 



Controls Employed in the Original Wassermann Technique. 

 — The original Wassermann technique for the diagnosis of syphilis 

 included many controls, a number of which are no longer em- 

 ployed. Citron (1909) has summarized the controls used in the 

 original technique somewhat as follows : 



1. The first control was to ascertain whether an aqueous ex- 

 tract of normal tissue (liver) and patient's serum would bind 

 complement. It was believed that tlie fixation of complement 

 depended upon spiroclietes being present in the antigen and cor- 

 responding antibodies in the serum. Hence, this control tube 

 should show no fixation of complement, as spirochetes were not 

 present in the normal liver. 



2. The second control was to show that known positive syph- 

 ilitic serum when mixed with an aqueous extract of a syphilitic 

 fetal liver containing spirochetes would fix complement. 



3. The third control was to show that positive syphilitic serum 

 would not fix complement in the presence of an aqueous extract 

 of normal tissue (liver). 



4 and 5. The fourth and fifth controls were to show that nor- 

 mal serum when mixed with an aqueous extract of either a syph- 

 ilitic or normal liver respectively would not fix complement. 



