define and describe  and antigenic determinant
From Wikipedia, the free encyclopedia. An epitope, also known as antigenic determinant, is the part of an antigen that is recognized by the immune system, specifically by antibodies, B cells, or T cells. For example, the epitope is the specific piece of the antigen to which an antibody binds. The part of an antibody that binds to the epitope is called a paratope.
an antigenic determinant located in an unexposed region of a molecule so that it is prevented from interacting with receptors on lymphocytes, or with antibody molecules, and is unable to induce an immune response; it may appear following stereochemical alterations of molecular structure.