TST

TST is an acronym that can refer to several different concepts across fields. The most commonly encountered meanings include the following.

Tuberculin skin test (TST) is a medical diagnostic tool used to detect latent tuberculosis infection. In this test, purified protein derivative is injected intradermally, and the injection site is examined after 48 to 72 hours for an area of induration. The size of the induration that is considered positive varies by the patient’s risk factors and history, and a positive result may prompt further evaluation for active tuberculosis. The TST can be influenced by prior Bacille Calmette-Guérin (BCG) vaccination and exposure to non-tuberculous mycobacteria, and it is increasingly complemented or replaced in some settings by interferon-gamma release assays (IGRAs).

Tail suspension test (TST) is a behavioral assay used in rodent studies to evaluate depressive-like states and the efficacy of antidepressant treatments. In this test, a mouse or rat is suspended by its tail, and the duration of immobility is recorded. Longer immobility times are interpreted as a measure of behavioral despair, while reduced immobility after drug treatment suggests antidepressant-like effects. The test is widely used in preclinical research but can be influenced by factors such as strain, age, and handling.

Taiwan Standard Time (TST) is a designation used in some contexts for the time zone of Taiwan, corresponding to UTC+8. Official timekeeping in Taiwan follows standard civil time standards and is commonly aligned with nearby regions, though time zone naming conventions can vary by system or publication.