A note on the interpretation of identity reactions in immunoelectrophoresis.

Immunoelectrophoretic methods, used in studies of the tissue specificity of two membrane-bound peptides obtained from pig, were observed to produce new types of reactions resembling those of partial immunochemical identity. In addition, the results obtained by fused rocket and rocket-line immunoelectrophoresis suggested that the unshared antigenic determinants were situated on the heterologous antigens. When analyzed in the immunodiffusion system, the antigens showed a reaction of total immunochemical identity. Zone electrophoresis of the antigens demonstrated large differences in electrophoretic mobility. Neuraminidase treatment of the antigens almost abolished these differences, and the antigens now exhibited almost complete antigenic identity, suggesting that the precipitate patterns observed arose from the mobility differences.