General Features of Antigen-antibody
reactions have the following general characteristics:
1. The reaction is specific. An antigen
combines only with its homolo-gous antibody and vice versa. The specificity,
however is not ab-solute and cross reaction may occur due to antigenic
similarity and relatedness.
molecules react and not fragments.
3. There is no denaturation of the
antigen or the antibody during the reaction.
4. The combination occurs at the
5. The combination is firm but
reversible. The firmness of the union is influenced by the Affinity and the
Avidity of the reaction. Affinity refers to the intensity if interaction
between the Antigen and Anti-body. Avidity is the strength of the bond after
the formation of the complexes.
6. Both antigens and antibodies
participate in the formation of agglu-tinates or precipitates.
7. Antigens and Antibodies can combine
in varying proportion