Radioelectrocomplexing: a counterelectrophoretic method for hapten--antibody interaction.

We have described an application of a radioimmunoassay (RIA)method, known as radioelectrocomplexing (REC), which involves the anodal migration of antigen and the cathodal migration of antibody in agar electrophoresis. The agar is divided into zones of free antigen (DNP125I-HSA) and antigen bound with anti-DNP. Complete assays of anti-DNP can be performed in 2-4 hr since both immune complex formation and separation of free from bound antigen can be accomplished by electrophoresis in 60-90 min. Estimation of the weight of specifically-purified anti-DNP chicken antibodies in the nanogram range by REC is of the same order as the reported sensitivity of other RIA methods. The method was capable of demonstrating the higher avidity of the 17 S than 7 S antibody. Based on hapten inhibition the relative binding constants of DNP derivatives and anti-DNP were of the same order as reported from more definitive methods.