Investigation of latex agglutination with different immunoglobulin classes of antibodies by a scanning electron microscopy.

The conformation of passive latex agglutinations was investigated by a scanning electron microscopy. The complexes of 2,4-dinitrophenyl group (DNP) and bovine serum albumin (BSA) coated microspheres were incubated with monoclonal antibodies to DNP belonging to different classes of immunoglobulins. Examination with a scanning electron microscope demonstrated that the connectors between microspheres, agglutinated with IgE antibody, tended to take long filamentary forms; whereas the connectors of microspheres, agglutinated with IgG or IgM antibodies, formed shorter filaments. These phenomena were confirmed by the agglutination reactions of tick suspension-coated latex and allergic patients' sera. This morphologic difference is probably attributable to the unusually high elasticity of IgE antibody and is an evidence of the high biologic activity of the IgE antibodies. We assumed the processes of latex agglutination whereby the filamentary substances would develop, expecting that the processes could be models of in vivo and in vitro agglutination of cells.