430 IMMUNOLOGY 



he prepares the following higher dilutions, 1 :160, 1 :320, 1 :640, 

 1 :1,280 and 1 :2,560. 



He then prepares 5 dilutions of inactivated positive serum in 

 such a way that by pipetting 0.5 c.c. of each he can arrange six 

 sets of 5 test tubes in a rack with the amounts of serum shown in 

 the following protocol. Each tube also has 0,5 c.c. of the antigen 

 dilution indicated. 



Antigen Titration 



antigen in 0.5 c.c. amounts 



Kolmer defines the dose of antigen to be used in the Kolnier 

 complement fixation test as the lai-gcst amount of antigen giving 

 a 4r>t- reaction with the smallest amount of serum. He says that, 

 if three dilutions all give 4 plus reactions with the smallest amount 

 of serum, one should choose a dose midway between the highest and 

 lowest. In the above protocol the test dose would be 0.5 c.c. of a 

 1 :320 dilution. 



As mentioned previously in this chapter the technique of the 

 Kolmer complement fixation test used to detect syphilitic reagin is 

 the same as that described in the previous chapter for bacterial 

 complement fixation except for the antigens used. The lipoid 

 antigen is substituted for the bacterial antigen in the Kolmer 

 modification of the Wassermann. 



The tests are also reported the same. It will be recalled that the 

 committee on the Evaluation of Serodiagnostic Tests for Syphilis 

 of the United States Public Health Service cooperating with the 

 American Society of Clinical Pathologists recommend that four 

 plus, three plus, two plus or one plus reactions in the first tube be 

 reported positive while plus or minus be called doubtful and com- 

 plete hemolysis negative. Kolmer, however, prefers to call four 

 plus and three reactions in the first tube as strongly positive, two 

 plus reactions or one plus reactions as weakly positive and plus- 

 minus as doubtful reactions and complete hemolysis in first tube as 

 negative. 



