Immunological properties of ornithine decarboxylase from regenerating rat liver and cultured rat hepatoma cells

A specific antibody against a purified preparation of ornithine decarboxylase (ODC) was used to investigate the conditions for optimal antigen antibody (Ag/Ab) reaction. When the Ab was tested against ODC from regenerating rat liver either in its crude or purified form, an identical equivalence point was observed. The same equivalence point was observed with immunoprecipitation when the Ab was tested against ODC isolated from log phase cultured rat hepatoma (HTC) cells. Crude extracts of both log and stationary phase HTC cells were analyzed by titration with the antibody to rat liver ornithine decarboxylase and by heat stability. The authors' studies show that these methods readily distinguish ODC of mammalian origin from that of bacterial origin.