Quantitative Changes in Antibodies and Globulin Fractions in Sera of Rabbits Injected with Several Antigens

Simultaneous measurements of the globulins (by Howe's method) and antibody (in terms of milligrams per milliliter in sera of rabbits immunized with different combinations of antigens, confirm previous work, showing an almost invariable rise in the globulins, affecting most the fractions precipitated by 13.5 and 17.4 per cent Na₂SO₄. These fractions contained the antibody in most instances. The amount of antibody produced never exceeded 35 per cent of the globulins in the serum, but in some cases exceeded the amount of any one of the three fractions of globulin. There was some evidence that simultaneous injection of many antigens produces less total antibody than the injection of only a single antigen.