Antibody

An immunoglobulin protein produced by B- lymphocytes of the immune system that binds to a specific antigen molecule. (See monoclonal antibodies, polyclonal antibodies.)

(Abbreviation: Ab). An immunological protein produced by the lymphocytes in response to contact with an antigen. Each antibody recognizes just one antigenic determinant of one antigen and acts by specifically binding to it, thus rendering it harmless. Those from the IgG antibody class are found in the bloodstream and used in immunoassay. Synonym: immunoglobulin. See: monoclonal antibody, polyclonal antibody.

(AN-tee-BAH-dee) A type of protein made by plasma cells (a type of white blood cell) in response to an antigen (foreign substance). Each antibody can bind to only one specific antigen. The purpose of this binding is to help destroy the antigen. Antibodies can work in several ways, depending on the nature of the antigen. Some antibodies destroy antigens directly. Others make it easier for white blood cells to destroy the antigen.

A specialized serum protein (immunoglobulin or gamma globulin) produced by B lymphocytes in the blood in response to an exposure to foreign proteins ("antigens"). The antibodies specifically bind to the antigens that induced the immune response. Antibodies help defend the body against infectious agents such as bacteria, viruses or parasites.

A blood protein that is produced in response to and counteracts an antigen. Antibodies are produced in response to disease and help the body fight against the particular disease. In this way, antibodies help the body develop an immunity to disease. See also lymphocyte, protein

A Y-shaped protein secreted by B cells in response to an antigen. An antibody binds specifically to the antigen that induced its production. Antibodies directed against antigens on the surface of infectious organisms help eliminate those organisms from the body.