1Generally proteins but can be lipids,Antibodies are proteins carbohydrates or nucleic acids 2Triggers the formation of antibodiesVariable sites has the antigen binding domain.3There are three basic kinds of antigens.There are five basic kinds of antibodies. (Exogenous, Endogenous and Autoantigens)(Immunoglobulins M, G, E, D and A)4The region of the antigen that interacts with theThe variable region of the antibody that specially antibodies is called epitopesbinds to an eoitope is calle paratope.5Cause disease or allergic reactionsProtects the body by immobilization or lysis of antigenic material