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antigen

play
noun an·ti·gen \ˈan-ti-jən, -ˌjen\

Simple Definition of antigen

  • medical : a harmful substance that causes the body to produce antibodies

Source: Merriam-Webster's Learner's Dictionary

Full Definition of antigen

  1. :  any substance (as an immunogen or a hapten) foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (as a protein) and that is capable of binding with a product (as an antibody or T cell) of the immune response

antigenic

play \ˌan-ti-ˈje-nik\ adjective

antigenically

play \-ni-k(ə-)lē\ adverb

antigenicity

play \-jə-ˈni-sə-tē\ noun

Did You Know?

An antibody is a protein produced by your immune system to fight outside invaders. Since the enemy substance actually triggers the production of antibodies, such substances are called antigens—anti- being short for antibody, and -gen meaning "producer". (In a similar way, an allergen produces an allergy, and a pathogen produces a pathology or disease.) Antigens are often rodlike structures that stick out from the surface of an invading organism—usually a bacterium or a virus—and allow it to attach itself to cells in the invaded body. But unfortunately for them, in doing so they let the immune system know they're present, and the body is flooded with an army of Pac-Man-like antibodies.

Origin and Etymology of antigen

German, from French antigène, from anticorps antibody + -gène -gen


First Known Use: 1908


Medical Dictionary

antigen

play
noun an·ti·gen \ˈant-i-jən\

Medical Definition of antigen

  1. :  any substance (as an immunogen or a hapten) foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (as a protein) and that is capable of binding with a product (as an antibody or T cell) of the immune response

antigenic

\ˌant-i-ˈjen-ik\play adjective

antigenically

\-i-k(ə-)lē\play adverb


Illustration of antigen



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