An antigen is any substance that causes your immune system to produce antibodies against it. This means your immune system does not recognize the substance, and is trying to fight it off.
An antibody is a protein produced by the body's immune system when it detects harmful substances, called antigens. Examples of antigens include micr...
An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also form inside the body.
Abbas AK, Lichtman AH, Pillai S. Antibodies and antigens. In: Abbas AK, Lichtman AH, Pillai S, eds. Cellular and Molecular Immunology . 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 5.
Stedman's Online Medical Dictionary . www.stedmansonline.com/content.aspx?id=mirA1400011566&termtype=t. Accessed Sept. 9, 2015.
Antigens - illustration
An antigen is a substance that can provoke an immune response. Typically antigens are substances not usually found in the body.
Review Date: 7/15/2015
Reviewed By: Stuart I. Henochowicz, MD, FACP, Associate Clinical Professor of Medicine, Division of Allergy, Immunology, and Rheumatology, Georgetown University Medical School, Washington, DC. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.