Tuberculin is injected into the forearm to determine if the patient has been exposed to the bacteria causing tuberculosis. If the patent is infected, a small hard red bump will develop at the site of the injection, usually after 48 hours.

This test is referred to as the Mantoux Test, also known as the tuberculin skin test or TST. It was developed in the early 1900s by Charles Mantoux (1877-1947), building on the work of Robert Koch and Clemens von Pirquet. ]]>