QuantiFERON®-TB Gold Plus, 1 Tube - This test is a blood-based interferon-gamma release assay (IGRA) used as an aid in the diagnosis of Mycobacterium tuberculosis infection. It is an immune response-based, indirect test for M tuberculosis infection (including disease) and is intended for use in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations. Additional testing is needed to determine if a person who has tested positive has latent tuberculosis (TB) infection or TB disease.