: Mycobacterium tuberculosis DNA, Qualitative, Nucleic Acid Probe

: What the Test Measures

: The test detects DNA from Mycobacterium tuberculosis, the bacterium responsible for tuberculosis. It uses a nucleic acid probe technique, which identifies a specific genetic sequence unique to this organism. Your sample is processed in the laboratory to reveal whether that DNA is present.

: Why It May Be Ordered

: Your healthcare provider may order this test when tuberculosis is suspected based on symptoms such as a prolonged cough, fever, night sweats, or weight loss, or after known exposure to someone with tuberculosis. It can also be used to help confirm a diagnosis when other tests, such as imaging or cultures, are inconclusive.

: How the Sample Is Collected

: Depending on the reason for testing, the sample may be sputum, another body fluid, or a tissue specimen. Sputum is most common for suspected lung tuberculosis. The laboratory extracts and analyzes nucleic acids from the sample; collection instructions should be followed carefully because sample quality affects the result.

: What the Results Mean

: A positive result means tuberculosis bacterial DNA was detected and generally supports the presence of infection, though your provider will interpret it alongside your symptoms, history, and other tests. A negative result means the DNA was not detected, but it does not always rule out infection, especially if the sample was inadequate or the disease is outside the lungs.