126 



APPLIED IMMUNOLOGY 



the effects of treatment when tested with only one unit 

 of complement, because it was previously capable of 

 fixing two or more units. When we wish to determine 

 accurately the complement absorption power of a 



Fig. 14. — Showing arrangement of tubes in performance of Wassermann reaction 

 on one unknown case, with positive and negative controls. 



P.S.I. Tube containing patient's serum and 1 unit of complement. P.S.2. Tube 

 containing patient's serum and 2 units of complement. S.C. Serum control tubes, 

 without antigen. +1. +2. Tubes containing known syphilitic serum and 1 and 2 units 

 of complement respectively. —1,-2. Tubes containing known non-syphilitic serum 

 and 1 and 2 units of complement respectively. A.C. Antigen control, containing 

 a double dose of antigen. 



serum, in order to gauge the effects of treatment by 

 subsequent tests, tubes should be prepared in doing the 

 test containing two, three, or more units of comple- 

 ment in addition to the usual one unit (Fig. 14). 



