IMMUNOLOGY

Detailed explanation-1: -hapten, also spelled haptene, small molecule that stimulates the production of antibody molecules only when conjugated to a larger molecule, called a carrier molecule.

Detailed explanation-2: -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.

Detailed explanation-3: -Haptens are small well-defined chemical groups such as dinitrophenol (DNP) which are not immunogenic on their own but will react with preformed antibodies. To make a hapten immunogenic, it must be linked to a carrier molecule which is itself immunogenic.