Antigen

How to spell antigen

7 letters · 3 syllables

How to pronounce antigen

Say the part in capitals loudest.

What does antigen mean?

1. nounA substance, often a foreign protein, that triggers the immune system to produce antibodies against it.

Antigen in a sentence

• The vaccine introduces a harmless antigen so the body learns to fight the real virus.

• The lab test detects a specific antigen in a blood sample within minutes.

Where does antigen come from?

Language of origin: Greek

Antigen is a twentieth-century scientific coinage that compresses the phrase 'antibody generator' into a single word. The 'anti-' portion is borrowed straight from 'antibody', itself built on the Greek 'anti', meaning 'against', because antibodies act against foreign matter in the body. The '-gen' ending comes from the Greek root 'genes', meaning 'born' or 'producing', the same element that sits inside familiar words such as 'oxygen', 'hydrogen', and 'genesis'. Put together, the term names any substance that prompts the immune system to produce a defending antibody, so the word literally labels what it does: it generates an immune response. It entered medical and immunological English around the start of the 1900s as researchers were first mapping how the body recognises invaders, and the tidy 'anti' plus 'gen' construction is a useful reminder that the spelling carries no double letters or hidden vowels to trip over.

How the word is built

• anti- (from antibody)
• -gen (from Greek -genes: producing, generating)