BACTERIOLYSINS AND H&MOLYSINS 



125 



test tubes indicates a four plus reaction. Degrees 

 of haemolysis between these two extremes are 

 regarded as indicating a three, two or one plus 

 reaction. 



All glassware must be neutralized before being 

 used in any manner in connection with this test. 



The tubes for the reaction are set up and filled 

 according to the following table : Each test is done in 

 duplicate. 



Serum controls should completely 

 haemolyze on addition of sensi- 

 tized cells. 



Test tubes to be set up in dupli- 

 cate. 



After incubation four hours at 8 C. 0.25 cc. sen- 

 sitized cells are added to each tube. 



Various modifications of the technique of the 

 Wassermann reaction have been proposed from 

 time to time, notable modifications being those of 

 Noguchi and of Hecht and Weinberg. Because of 

 the fact that more than 50 per cent of human sera 

 contain a natural amboceptor for she,ep cells, and 

 because sheep cells are difficult to obtain in certain 

 localities, Noguchi proposed a test in which human 

 cells and anti-human amboceptor were used instead 

 of sheep cells. This test does not give as reliable 



