Reticulo-Endothelial Immune Serum (REIS). VI. Production of Potent Serum by Anamnestic Reaction.

Abstract

In the prepn. of antiorgan sera (REIS) the slow process of immunization of rabbits was adopted. A saline suspension of 400 mg. of spleen plus 100 mg. of bone marrow (guinea pig or rat) was injd. intraven. into rabbits at 4-day intervals and the same amts. were given by mouth over a period of 12 days. A high potency of the serum was achieved by the anamnestic response of the previously immunized rabbit to a single injn. of the antigen 30-40 days following the last injd. dose. The potency of the "anamnestic" serum as compared with the "primary" was evaluated by complement-fixation titres and by the tissue-culture assay method. In the latter, the degree of inhibition of cellular outgrowth from explants in a medium containing various concs. of REIS was measured.