Arkray Tuberculin PPD, also known as Purified Protein Derivative, is a substance used in the Mantoux test to detect tuberculosis infection. It's a standardized solution injected intradermally to assess for sensitization to Mycobacterium tuberculosis. The Mantoux test, or tuberculin skin test (TST), involves injecting a small amount of Tuberculin PPD into the skin, and the resulting skin reaction (induration) is measured to determine if a person has been exposed to TB bacteria.