agglutinin /əglo̅o̅″tinin/ , an antibody that interacts with antigens, resulting in agglutination. Usually multivalent, agglutinins react with insoluble antigens in stable suspension to form a cross-linking lattice that may clump or precipitate. Agglutinins are used in blood typing and in identifying or estimating the strength of immunoglobulins or immune sera. Compare precipitin. See also blood typing, hemagglutination.
