474 



THE TECHNIC OF COMPLEMENT-FIXATION REACTIONS 



antihuman hemolysin is at hand. Comparative tests using the anti- 

 sheep and antihuman hemolytic systems with the same sera have shown 

 that the degree of inhibition of hemolysis with positive sera is occasion- 

 ally greater with the antihuman system. 



Controls. The anticomplementary action of each serum is controlled 

 in the last two tubes of each series; unless a serum is markedly anti- 

 complementary, the use of 1 and 2 units of complement is sufficient. 



2. A known positive and negative serum may be included. 



3. A hemolytic control is set up with 1 unit of complement and 

 antigen; after the primary incubation 1 unit of hemolysin and the cells 

 are added. This tube is a control on the unit of complement and should 

 show complete hemolysis. 



4. A corpuscle control may be included, containing 0.5 c.c. of cor- 

 puscles and 3 c.c. of salt solution. It controls the tonicity of the salt 

 solution and should show no hemolysis. 



Reading the Results. The controls are first inspected. The corpus- 

 cle control should show no hemolysis and the hemolytic control be just 

 hemolyzed. The last two tubes of each series are the serum control tubes, 

 and the first tube containing 1 unit of complement may show incomplete 

 hemolysis, while the second tube containing 2 units of complement 

 shows complete hemolysis unless the serum is quite anticomplementary. 



TABLE 15b. RESULTS AND METHOD OF READING THE WASSER- 

 MANN REACTION (QUANTITATIVE METHOD) 



The first six tubes of each series show whether or not the reaction is 

 positive or negative, and if positive, the amount of complement absorbed. 

 If tube No. 7 of the serum controls shows some inhibition of hemolysis, 

 1 unit is subtracted from the number of units of complement absorbed 

 in the first six tubes, and the difference represents the amount of comple- 

 ment absorbed by antigen and syphilitic antibody. / regard the reaction 



