What Is an Antigen & an Antibody?
Both antigens and antibodies are part of the human body’s immune system. Antigens are usually large, complex foreign substances that cause the production of antibodies. A substance that has an antigen on the surface is antigenic. The body recognizes these foreign antigens as invaders and moves to destroy them with lymphocytes, or white blood cells, which secrete antibodies. Antigens may be found on the surface of things such as foods, red blood cells, cancer cells, and pollen. The body produces antibodies for the sole purpose of destroying antigens.
