Tuberculin: A protein extracted from Mycobacterium tuberculosis that is used in a skin test to determine if a person has been exposed to tuberculosis. The tuberculin preparation in most common use today is purified protein derivative (PPD) tuberculin. PPD is injected (or multiple-punctured) into the skin. If a reaction is seen at and around the site of injection, the test is positive. The PPD tuberculin test done by intradermal injection is also known as the Mantoux test.
Reviewed on 6/9/2016