TECHNIC OF WASSERMANN REACTION. 289 



question is carried out as follows: 0.1 c.c. of 

 inactivated serum to be tested is added to 0.1 c.c. 

 of complement and that amount of antigen added 

 which was found to be the minimum required to 

 bind complement in the presence of 0.1 c.c. of 

 syphilitic serum. Control tubes are made as fol- 

 lows: One positive control is made as the test 

 serum tube but with a like quantity of inactivated 

 known syphilitic serum in place of the serum to be 

 tested. One negative control is prepared with the 

 same components as the test serum tube except 

 that inactivated normal serum- is used instead of 

 the serum to be tested. Three control tubes are 

 made with the test serum in one, positive serum in 

 a second and the normal serum in the third, and 

 salt solution substituted for the antigen to ascer- 

 tain whether or not the serum alone causes com- 

 plement deviation. One control tube is made with 

 salt solution instead of serum to see if antigen 

 alone will bind complement. Another control may 

 be made with complement, human serum to be 

 tested and corpuscles to exclude hemolysins for 

 sheep's corpuscles being present in the human 

 serum. After incubation of the antigen, comple- 

 ment, serum mixtures and control tubes for one 

 hour, the hemolytic system, consisting of two 

 units of hemolytic amboceptor and 1 c.c. of 5 per 

 cent, corpuscle suspension, is added to each tube. 

 After a second incubation of one hour the tubes 

 are examined for hemolysis. There should be no 

 hemolysis in the positive control tube. In the 

 other control tubes complete hemolysis should have 

 taken place. If hemolysis is present in the tube 

 containing the test mixture the reaction is nega- 



