antigen
n. countablen. a substance that makes your immune system start fighting, often by creating antibodies. It is usually something from outside your body, like a virus or bacteria.
n. any substance that induces an immune response in the body, specifically the production of antibodies. Typically a protein or polysaccharide on the surface of a pathogen.
The vaccine introduces a harmless antigen to your body.
Doctors use a rapid test to detect the presence of a specific viral antigen in the patient's blood sample.
The immune system distinguishes between self and non-self by recognizing unique molecular patterns on the surface of the invading antigen, triggering a targeted defensive response.
From French antigène, from anti- + gène.
Commonly used in medical and biological contexts; often paired with verbs like 'detect', 'recognize', or 'bind'.