reaction

reaction The binding force between antigen and antibody is due to three factors . They are closeness between antigen and antibody, non- covalent bonds or intermolecular forces and affinity of antibody. When antigen and antibody are closely fitted, the strength of binding is great. When they are apart binding strength is low. The bonds that hold the antigen to the antibody combining site are all non-covalent in nature. These include hydrogen bonds, electrostatic bonds, Van der Waals forces and hydrophobic bonds . Antibody affinity is the strength of the reaction between a single antigenic determinant and a single combining site on the antibody. The chief application of antigen - antibody reactions are to determine blood groups for transfusion, to study serological ascertainment of exposure to infectious agents, to develop immunoassays for the quantification of various substances, to detect the presence or absence of protein in serum and to determine the characteristics of certain immunodeficiency diseases.