IMMUNOLOGY

Detailed explanation-1: -A hapten is essentially an incomplete antigen. These small molecules can elicit an immune response only when attached to a large carrier such as a protein; the carrier typically does not elicit an immune response by itself.

Detailed explanation-2: -Unlike antigens, haptens require an additional molecule before they are able to elicit an immune response. These additional molecules are called “carriers” and are often proteins to which the hapten binds to tightly; this is usually a covalent bond.

Detailed explanation-3: -A partial/incomplete antigen (haptens) are substances which are incapable of inducing antibody formation by themselves, but can be capable of inducing antibodies on combining with larger molecules which serve as carriers.

Detailed explanation-4: -A well-known example of a hapten is urushiol, which is the toxin found in poison ivy. When absorbed through the skin from a poison ivy plant, urushiol undergoes oxidation in the skin cells to generate the actual hapten, a reactive quinone-type molecule, which then reacts with skin proteins to form hapten adducts.