This test looks for a bacterium called Mycobacterium in a sample of sputum.
This test is ordered when tuberculosis or another kind of lung infection with a type (species) of Mycobacterium is suspected.
The test is performed on a sample of sputum, or deep phlegm. The person must cough hard and repeatedly to get the sputum up from the bottom of the lungs. When the sputum is in the throat and mouth, the person spits it into a container.
In the lab, the sputum is placed on a microscope slide, stained, heated, and treated with acid. If mycobacteria are seen, the sputum may be put on a culture dish to see if more organisms can be grown.
The healthcare professional will provide specific instructions.
Normally, no mycobacteria are observed. If the test is positive, the lung infection is most likely caused by a Mycobacterium species.