Table 6.

Summary of the M27 method developed by the NCCLSa

FactorImplementation in the M27 methodology
MethodologyBroth macrodilution, 1-ml final volume; or broth microdilution, 0.2-ml final volume
MediumRPMI 1640 containing 0.165 M MOPSb (pH 7.0)
Fungal inoculum(0.5–2.5) × 103 organisms
Incubation temp35°C
Incubation time48 h (Candida species) or 72 h (Cryptococcus neoformans)
End pointAmphotericin B, optically clear tube; azoles and 5-FC, 80% reduction in turbidity by comparison with growth control
Drug and quality control (QC) isolates  Two QC isolates and corresponding QC ranges established via the M23 procedure are specified for amphotericin B, flucytosine, ketoconazole, itraconazole, and fluconazole
  • a Adapted from reference217 with permission of the publisher.

  • b Morpholinepropanesulfonic acid.