Antibodies against hapten of 7S and macroglobulin type in chickens

The course of antibody formation of the macroglobulin type and of the 7S type was studied in chickens after a single and repeated injections of immunizing doses. In chickens immunized with 2 ml. of 50% suspension of sheep erythrocytes the titres of antibodies reached a maximum on the 5th day after immunization. These antibodies were mainly of the macro-globulin type. After immunization of chickens with a single dose of 50 mg. of p-ABA-HSA intravenously, a steep rise in anti-HSA antibodies was demonstrated already on the 3rd day, whereas antibodies to hapten appeared on the 7th day after immunization. Preparative ultracentrugation analysis showed that on the 7th day after immunization the higher proportion of anti-HSA antibodies were of macroglobulin type and anti-hapten antibodies were exclusively macroglobulins. In animals repeatedly immunized at weekly intervals with 40 mg. of p-ABA-HSA, anti-hapten antibodies of the 7S type also appeared after the third dose but macroglobulin antibodies predominated even after the 5th immunization.