Enumeration of Antibody-Forming Cells in the Peripheral Blood of Immunized Rabbits

Abstract

Rabbits were injected with sheep erythrocytes, and their blood leukocytes were separated at intervals and examined by the agar plaque technique for cells producing specific antibody. In a typical experiment, no active cells appeared after the first injection, but a second stimulus consistently produced antibody-forming cells in considerable numbers (up to several hundred/ml of blood). These cells first appeared on the 2nd day after the second antigen injection, reached a maximum on the 3rd day and rapidly declined. Subsequent injections gave rise to smaller responses. An attempt was made to estimate the efficiency of the separation procedure. Splenectomy of the rabbit had no significant effect on the occurrence of antibody-forming cells in the blood.