Solid phase immunosorbent technique (SPIT) for the demonstration of specific IGM antibodies by hemagglutination inhibition and passive hemagglutination.

The adsorption of protein to glass and plastic has been well documented. It has also been demonstrated that the absorbed antigen or antibodies retain their activity in as much as they are able to react with a specific antibody respective specific antigen(1). Furthermore the adsorbed antignene or antibody complex may also react with a later added antigen. Anti IgM is adsorbed to the solid phase and will retain IgM from the patient's serum. If the patient's serum contains specific IgM this will react with the specific antignene. If the antigen is a hemagglutinin it will combine with the specific IgM and therefore added erythrocytes will not hemagglutinate. If the antigen is coated on erythrocytes the coated erythrocytes will combine with the specific IgM and hemagglutination will take place. The reaction is schematically demonstrated in Fig. 1.