Elimination of Host Tissue Reactions in Immunodiffusion and Immunoelectrophoretic Studies of Arboviruses ∗

Summary

Host tissue reaction was a stumbling block in the progress of immunodiffusion and immunoelectrophoretic studies of arboviruses in this laboratory. Partial purification by flurocarbon or by protamine sulfate, of the infected rodent brain tissue homogenates used as test antigens or as inocula into rabbits to prepare antisera failed to remove the tissue antigen reactions. Antisera prepared against infected mouse brain or normal mouse brain reacted with normal hamster brain and vice versa. However, two methods were successful in eliminating the reaction: (i) Pellets obtained from clarified infected mouse brain homogenates following ultracentrifugation at 106,000g was free from rodent brain antigen but contained reacting viral antigens. (ii) Absorption of antisera either by 50% normal mouse brain or normal hamster brain eliminated the antibodies to the rodent brain tissue antigens. Two methods accomplished this latter—conventional tube absorption or absorption-in-gel. The latter is described in detail and found to be highly effective, simple, easy, time saving, and sparing of reagents. It is now used routinely in this laboratory.