Part III 



SERUM DIAGNOSIS 



Chapter XII 



COMPLEMENT FIXATION 



A detailed account of the immunologic meth- 

 ods of diagnosis would lead us too far and would 

 indeed furnish sufficient material for a special 

 volume. Moreover, the technic employed in se- 

 rum diagnosis is such that results can only be 

 elicited with any degree of accuracy by skilled 

 laboratory workers. Nevertheless, it may not 

 be out of place to consider here some of the more 

 important methods ; for every physician should 

 know the significance, the general facts and the 

 practical application of these methods. 



Nature of Reagents Used The principle of 

 complement fixation, discovered in 1901 by 

 Bordet and Gengou (Annales de I'lnstitut 

 Pasteur, 1901, xv, 290), has been utilized both 

 in bacteriologic investigations and in practical 

 diagnosis for the determination in serum of the 



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