SERUM DIAGNOSIS OF ECHINOCOCCUS DISEASE. 



IV. Serum Diagnosis of Echinococcus Disease. 



171 



The technique of this reaction is practically the same as described for 

 the Wassermann test. 



As antigen the cystic fluid of the human being or sheep is employed. 

 The latter according to Weinberg is preferable, as human hydatid fluid 

 sometimes reacts with normal serum. 



The following is Weinberg's outline for performing the test: 



Bauer's modification as employed for the Wassermann test can also be 

 employed here. 



V. The Differentiation of Proteids by the method of Neisser and Sachs. 



This technique varies only in a few details from the method advanced 

 later on by Wassermann and Bruck for the diagnosis of bacterial infections. 



Neisser and Sachs do not employ a constant amount of complement (o.i), but first 

 titrate the complement against a dose of hemolysin double its hemolytic titer. For the 

 test one and a half to two times the complement titer is necessary. The hemolysin 

 consists of the serum of a rabbit immunized against ox's blood. This hemolysin acts 

 both for ox's and sheep's erythrocytes. 



The amount of antiserum (for example antihuman serum) used for the 

 test, is influenced by two factors. 



1. An excess of antiserum can interfere with the fixation of complement. 



2. The antiserum if used in large quantities can bind complement of its 



