Appendix 5. Time required for diagnostic test results

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    Update: October 2022



    Estimated time for results

    Additional time for DST

    Xpert MTB/RIF

    110 minutes


    Xpert MTB/RIF Ultra

    < 80 minutes


    Xpert MTB/XDR

    < 90 minutes



    35 minutes (Truenat MTB)

    1 hour (Truenat MTB-RIF Dx)

    Culture liquid medium
    (MGIT (a) Citation a. Mycobacteria growth indicator tube. )

    8 days (smear+)
    16 days (smear−)

    2 weeks

    Culture solid medium

    LJ standard medium

    16 days (smear+)
    29 days (smear–)

    6 weeks

    Culture microcolonies
    (TLA (b) Citation b. Thin-layer agar. , MODS (c) Citation c. Microscopic observation of drug susceptibility. )

    14 days

    Smear microscopy

    2 hours


    GenoType MTBDRplus (V2.0)

    1 to 2 days (direct testing on smear+)

    21 days (indirect testing)


    GenoTypeMTBDRsl (V2.0)

    1 to 2 days (direct testing)

    21 days (indirect testing)


    25 minutes


    1 to 3 days (direct testing on smear+)

    21 days (indirect testing)


    21 days (indirect testing)

    Note: to provide negative results, cultures need to be incubated for 6 to 7 weeks on liquid media and 8 weeks on solid media.

    • (a)Mycobacteria growth indicator tube.
    • (b)Thin-layer agar.
    • (c)Microscopic observation of drug susceptibility.