470 THE TECHNIC OF COMPLEMENT-FIXATION REACTIONS 



Tube 1 

 Tube 2 

 Tube 3 

 Tube 4 

 Tube 5 

 Tube 6 

 Tube 7 

 Tube 8 



0.01 c.c. serum 100 



0.02 c.c. serum 100 



0.04 c.c. serum 30 



0.06 c.c. serum 10 



0.08 c.c. serum 4 



0.1 c.c. serum 4 



0.2 c.c. serum 2 



0.2 c.c. serum (control) 100 



. Although these figures suffice for recording purposes, they are not 

 adapted, without some qualifying phrase, for rendering reports to 

 clinicians. According to the inhibition of hemolysis or the degree of 

 hemolysis in the sixth tube containing the maximum quantity of 

 serum the following scheme may be used in reporting the results : 



to 10 = strongly positive = 

 10 to 30 = moderately positive = 

 30 to 50 = slightly positive = ( + +) 

 50 to 80 = very weakly positive = (+) 

 80 to 90 = doubtful or delayed hemolysis =(=*=) 

 100 = negative = ( ) 



TECHNIC OF THE FOURTH METHOD 

 WASSERMANN REACTION WITH VARYING AMOUNTS OF COMPLEMENT 



In this method the amount of syphilis antibody in a serum is meas- 

 ured according to the number of hemolytic doses of complement ab- 

 sorbed or fixed with a constant amount of antigen. As previously 

 stated, any organic extract used as antigen may of itself fix a certain 

 amount of complement; a non-syphilitic serum may do the same, 

 and a mixture of the two may fix still more, though the amounts may 

 be relatively small. A peculiarity possessed by a syphilitic serum is 

 that it fixes a large amount of complement when mixed with antigen; 

 as a result the test becomes a quantitative and not a qualitative reac- 

 tion. The only practical means we possess of estimating the amount 

 of complement in a fresh serum is to ascertain the hemolytic dose, 

 i. e., to find the smallest quantity of serum that is just sufficient com- 

 pletely to lyse the test amount of corpuscles with the hemolysin. When 

 this has been done, the quantity of complement used in. the reaction 

 may be expressed in terms of hemolytic doses fixed, and not in terms 

 of the amount of fresh serum. 



When properly performed according to this method, which has 

 been modified after the technic of Browning and Mackenzie 1 and 

 1 Ztschr f. Immunitatsf., orig., 1909, 2, 459. 



