The PPD test is typically administered by an intradermal injection of 0.1 ml of PPD antigen into the inner surface of the forearm, using a tuberculin syringe with the needle bevel facing upwards. Following the injection, the test area is evaluated by a physician 48 to 72 hours later. During this period, slight redness or swelling may be observed at the injection site; these reactions are carefully examined by the physician. The presence or absence of any reaction in the skin against PPD is assessed. If the PPD test result is positive based on these findings, tuberculosis may be diagnosed in the individual.