This test uses a microscope to detect bacteria called acid-fast bacilli in fluid or tissue samples. This test is used to manage mycobacterial infections such as tuberculosis. A sample of sputum, bronchial samples, blood, cerebrospinal fluid, urine, stool, or other body fluids or tissues may be collected for this test. An acid-fast Bacillus (AFB) culture refers to the process of detection, growth, isolation, identification, and antibiotic susceptibility testing of Mycobacteria that cause pulmonary tuberculosis and other infections such as those of the skin, abdomen, and may widely spread throughout many organs. It has become important in the identification of other acid-fast AFB such as Mycobacterium tuberculosis and M. leprae, M. avium complex (MAC), M. bovis, and M. africanum. They are used to help determine whether the TB is confined to the lungs (pulmonary disease) or has spread to organs outside the lungs (extrapulmonary disease). AFB cultures can also be used to monitor the effectiveness of treatment and can help determine when a patient is no longer infectious.