noun
antigenic determinant; epitope
Technical term in immunology; the specific part of an antigen recognized by an antibody or T-cell receptor.
抗原決定基は抗体が結合する抗原の一部分です。
An epitope is the part of an antigen to which an antibody binds.
Compound of 抗原 (kōgen, 'antigen') + 決定 (kettei, 'determination') + 基 (ki, 'group, radical'), calque of English 'antigenic determinant'.