Detect and identify Mycobacterium tuberculosis complex and an rpoB mutation that is associated with rifampin resistance. Per the College of American Pathologists (CAP) guidelines (MIC.64820), a culture should be performed on all samples regardless of the molecular test result.

The assay should not be used to test specimens from patients that have been treated with antituberculous drugs for more than three days. The assay should not be used to monitor therapy or as a test of cure. A negative test does not exclude the possibility of isolating M tuberculosis complex isolates from culture. Assay interference may occur in the presence of lidocaine, mucin, ethambutol, guaifenesin, phenylephrine, and tea tree oil.

Lower sensitivity may be observed in pediatric patients due to the diffuse nature of Mtb infection in the lungs of this patient group and difficulties encountered in obtaining adequate specimens.

Sterile container

Sterile vial/container

Refrigerated (preferred) – 7 days

Ambient – 3 days

Frozen –  OK (below -70 °C)

• Quantity not sufficient (QNS)
• Inappropriate specimen source
• Specimen received after leaking out of transport container into the specimen bag
• Inappropriate or expired specimen transport device
• Specimen received after prolonged delay (more than seven days unless frozen)
• Specimen in fixative
• Specimen in a paraffin block

Nucleic acid amplification (NAA) technology; nested real-time polymerase chain reaction (PCR)

Concentrated specimen with broth-based and/or agar-based culture. Culture is held for six weeks before negative is reported. Organisms from culture are identified by use of real-time polymerase chain reaction (PCR) and/or MALDI-TOF and/or nucleic acid sequencing.

Not detected; see report for interpretation