cobas® MAI

Qualitative nucleic acid test for use on the cobas® 6800/8800 Systems


The right result the first time


Nontuberculous mycobacteria (NTM) are mycobacterial species other than M. tuberculosis and M. leprae. NTMs are found ubiquitously in the environment, including soil and water. Although NTM can colonize body surfaces and secretions without causing disease, they have been associated with four distinct clinical syndromes; progressive pulmonary disease (MAC, M. kansasii, M. abscessus), superficial lymphadenitis, seen commonly in pediatric populations, (MAC, M. scrofulaceum, M. malmoense), disseminated disease in severely immunocompromised patients, and skin and soft tissue infection usually as a consequence of direct inoculation.1,2 Mycobacterium avium and M. intracellulare are two closely related, distinct species of nontuberculous mycobacteria (NTM), which comprise the M. avium complex (MAC), and may also be grouped together as M. avium intracellulare (MAI). MAC is primarily a pulmonary pathogen that affects individuals who are immune compromised (e.g., patients with AIDS, cancer, receiving hematologic and solid organ transplants, or on immunosuppressive chemotherapy).4 NTMs, including MAC, should be identified to species level.1,3 cobas® MAI provides a solution to detect and differentiate Mycobacterium avium and Mycobacterium intracellulare DNA in human respiratory specimens providing important information for patient care decisions. This test is intended for use in conjunction with culture as an aid in the diagnosis of M. avium-intracellulare complex (MAC) infection.

cobas MAI The bacteria can be found in places such as:

Delivering exceptional assay performance


cobas® MAI is a duplex test designed to detect and differentiate Mycobacterium avium and Mycobacterium intracellulare DNA. Selective amplification of target nucleic acid from the sample is achieved by the use of target-specific forward and reverse primer for the M. avium complex which is selected from a highly-conserved region within the respective target organism. MAC is detected by one selective set of primers and M. avium and M. intracellulare are differentiated by two distinct probes within the amplification region (16S rRNA gene).

Key performance characteristics


Sensitivity and Specificity

cobas® MAI for use on the cobas® 6800/8800 Systems demonstrated comparable performance to existing molecular assays available for both raw sputum & sediment specimens.


Package inserts

Access package inserts through your country’s Roche Diagnostics Website.



  1. Griffith DE, Aksamit T, Brown-Elliott BA, et al. An official ATS/IDSA statement: diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases. AmericanJ Respir Crit Care Med. 2007;175:367-416. 
  2. Center for Disease Control and Prevention. Biosafety in microbiological and biomedical laboratories, 5th ed. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institutes of Health HHS Publication No. (CDC) 21-1112, revised December 2009.
  3. Haworth CS, Floto RA. Introducing the new BTS Guideline: Management of non-tuberculous mycobacterial pulmonary disease (NTM-PD). Thorax. 2017 Nov;72(11):969-970 
  4. Henkle E and Winthrop K. Nontuberculous Mycobacteria Infections in Immunosuppressed Hosts. Clin Chest Med. 2015 March ; 36(1): 91–99. Thorax. 2017 Nov;72(11):969-970

cobas® MAI Product Summary

  • Sample types

    - raw sputum

    - NALC/NaOH-treated sputum and bronchoalveolar (BAL) sediments

  • Amount of sample

    Sputum is ≥ 0.4mL

    Sediment is ≥ 0.2mL

  • Sample processing

    Manual liquefaction and inactivation followed by sonication and automated amplification and detection on the cobas® 6800/8800 Systems.

    Total duration < 3.5 hours.

  • PCR target region

    16S rRNA gene

  • Internal control


  • Inclusivity

    M. intracellulare, M. arosiense, M. chimaera, M. colombiense, M. indicus pranii, M. marseillense, M. timonense, M. vulneris, M. yongonense, M. avium, M. avium supsp. avium, M. avium supsp. hominissuis, M. avium supsp. paratuberculosis, M. avium supsp. silvaticum, M. bouchedurhonense

  • Analytical specificity

    A panel of 173 bacteria, fungi and viruses, including those commonly found in respiratory tract did not interfere with the test by generating false positive results.

  • Analytical sensitivity - Limit of detection

    M. intracellulare: 42.5 CFU/mL (sputum/BAL sediment), 46.6 CFU/mL (raw sputum)

    M. avium: 43.5 CFU/mL (sputum/BAL sediment), 44.9 CFU/mL (raw sputum)

Ordering information
Product name P/N
cobas® MAI 08412138190
cobas® MAI Positive Control Kit 07544863190
cobas® 6800/8800 Buffer Negative Control Kit 07002238190
cobas® Microbial Inactivation Solution (MIS) 08185476001

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