In the<unk> , a standard dose of 5 tuberculin units (TU - 0.1 ml), according to the CDC, or 2 TU of Statens Serum Institute (SSI) tuberculin RT23 in 0.1 ml solution, according to the National Health Service, is injected intradermally (between the layers of dermis) on the flexor surface of the left forearm, mid-way between elbow and wrist. The injection should be made with a tuberculin syringe, with the needle bevel facing upward. Alternatively, the probe can be administered by a needle-free jet injector. When placed correctly, injection should produce a pale wheal of the skin, 6 to 10 mm in diameter. The result of the test is read after 48–96 hours but 72 hours (3rd day) is the ideal. This intradermal injection is termed the<unk>  technique. A person who has been exposed to the bacteria is expected to mount an immune response in the skin containing the bacterial proteins. The response is a classical example of delayed-type hypersensitivity reaction (DTH), a type IV of hypersensitivities. T cells and myeloid cells are attracted to the site of reaction in the timeframe of 1–3 days and generate local inflammation. The reaction is read by measuring the diameter of induration (palpable raised, hardened area) across the forearm (perpendicular to the long axis) in millimeters. If there is no induration, the result should be recorded as "0 mm". Erythema (redness) should not be measured. In the Pirquet version of the test tuberculin is applied to the skin via scarification.
Mantoux test
Heterophile antibody test
T-SPOT.TB
Rabbit test
Widal test
GeneXpert MTB/RIF
Direct fluorescent antibody
Mouse ear swelling test