: Mycobacterium avium Complex rRNA Qualitative Probe Test, Specimen

: What This Test Detects

: The test looks for ribosomal RNA (rRNA) specific to Mycobacterium avium complex, a group of closely related bacteria that includes Mycobacterium avium and Mycobacterium intracellulare. Because rRNA is present in active organisms, a probe that binds MAC rRNA provides evidence that these bacteria are present in the sample.

: Why It Is Ordered

: Healthcare providers may order this test when they suspect a mycobacterial infection, particularly in people with weakened immune systems or chronic lung disease. It can help confirm whether MAC is the cause of an infection when other culture or staining results are inconclusive or slow to return.

: How the Test Is Performed

: A specimen is collected by your healthcare provider—commonly respiratory fluid such as sputum or a sample obtained by bronchoscopy, though other specimen types may be used depending on your situation. The laboratory processes the sample and uses a nucleic acid probe designed to bind specifically to MAC rRNA. The result is reported as positive (detected) or negative (not detected).

: What the Results Mean

: A positive result means MAC rRNA was detected, suggesting these bacteria are present in the specimen. A negative result means the probe did not detect MAC rRNA. Results are interpreted alongside your symptoms, imaging, and other laboratory tests; a single result does not by itself establish a diagnosis, and your provider will determine what further evaluation or treatment is appropriate.