Medical Dictionary

antigen

noun an·ti·gen \ˈant-i-jən\

Medical Definition of ANTIGEN

:  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
an·ti·gen·ic \ˌant-i-ˈjen-ik\ adjective
an·ti·gen·i·cal·ly \-i-k(ə-)lē\ adverb

Illustration of ANTIGEN

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