A SIMPLE METHOD OF QUANTITATIVE DETERMINATION OF COMPLEMENT FIXATION
Joseph O. Hirschfelder · JAMA · 1916
In the complement fixation test the purpose is to determine the presence or absence in the serum to be tested of a body which on uniting with the antigen will prevent the complement from combining with the lysin to dissolve the blood cells. In the antigen we have a complement fixing body (A) and a substance (B) which unites with the antibody in the serum to form a complement fixing substance. Similarly, in the serum we have a complement fixing body (C) and the antibody (D). The problem is to find the presence or absence of the antigenic substance and the specific antibody (BplusD) which on uniting fix the complement. If we wish to know how much of the latter combination is present, it is evident that we must first determine the amount of the anticomplementary action of the antigen and of the serum alone, as these vary.