Description. Tuberculin purified protein derivative (PPD) is used in a skin test to help diagnose tuberculosis (TB) infection in persons at increased risk of developing active disease. Tuberculin skin test is done by injecting tuberculin PPD into the surface layer of the skin. If the test is positive, a reaction will be seen at and around the ... More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.