Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Hapten
Medically reviewed by Min Clinic Staff | Updated: January 2026
Hapten: In immunology, a molecule that is incapable, alone, of causing the production of antibodies but which can do so when fastened to a larger antigenic molecule called a carrier.
The term "hapten" was taken from the Greek verb "haptein" meaning "to fasten or bind." Haptin and haptene are alternative forms of this term that was first introduced into usage by the pioneering German bacteriologist and immunologist Paul Erlich (1854-1915).