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THE TECHNIQUE OF COMPLEMENT FIXATION. 



2. Inactivated immune serum + complement (five hours) + hemolysin + blood. 

 Hemolysis results. 



3. Inactivated normal serum + complement (five hours) + hemolysin + blood. He- 

 molysis. 



4. Antigen + inactivated immune serum + hemolysin + blood. No hemolysis, as 

 complement is absent. 



5. Antigen + inactivated normal serum (five hours) + hemolysin + blood. No 

 hemolysis, as complement is absent. 



The following is the chart of the first complement fixation test as originally performed 

 by Bordet and Gengou in 1901 in which pest antibodies were demonstrated in the serum 

 of an immunized horse. 



Employing this method, Bordet and Gengou found positive results with the following 

 combinations: 



1. Pest bacilli + pest horse's serum + guinea-pig complement + guinea pig hemolysin 

 + rabbit's blood. 



2. Anthrax vaccine + guinea-pig immune serum + guinea-pig complement + guinea-pig 

 hemolysin + rabbit's blood. 



3. Typhoid bacilli -1- guinea-pig immune serum + guinea-pig complement + guinea- 

 pig hemolysin + rabbit's blood. 



4. Coli bacilli + guinea-pig immune serum + guinea pig complement + guinea-pig 

 hemolysin -I- rabbit's blood. 



