STUDIES ON ANTIBODY PRODUCTION : VI. THE COURSE, SENSITIVITY, AND HISTOLOGY OF THE SECONDARY RESPONSE IN VITRO.

The in vitro anamnestic antibody response of popliteal lymph node fragments to additions of antigen closely resembles the in vivo anamnestic antibody response in its sensitivity to antigen, in the time course of antibody production, and in the sequence of appearance and the morphology of the antibody containing cells. Most of the cells responsible for antibody synthesis remain in the explant and do not migrate, although a few can be found in the outgrowing sheet of cells. The smallest concentration of bovine serum albumin which stimulates an anamnestic response in vitro is about 1 x 10(-9) gm/ml.