Rabbit C3 isolation and characterization of reactions in vitro and during in vivo antigen-antibody interaction.

Rabbit C3 has been identified in serum by agarose gel electrophoresis and by immunoelectrophoresis, and it was shown that calcium ions slow its mobility. It was purified by methods previously used for human C3. Characteristic conversion products similar to those in other species were produced after various in vitro treatments. Reproducible changes occurred during sub-anaphylactic antigenic challenges in the rabbit which were reflected in total serum complement activity. Anaphylactic death was associated with profound changes in haemolytic complement and C3. These findings provide a basis for further study in the rabbit during experimental immunological disease.