The EUCAST disk diffusion test is based on MH media and disks of a good quality. It is calibrated to EUCAST clinical breakpoints using broth microdilution for MIC determination. Updates are published regularly. 

The EUCAST Development Laboratory has systematically investigated the quality of MH-powders, antibiotic disks and of pre-poured MH plates for disk diffusion. The publications from these investigations are available from the EUCAST website (antibiotic disk quality, MH powder quality, the quality of pre-poured MH plates). 

See also EUCAST instruction videos with subtitles in many languages.

• Disk diffusion manual v 13.0 (1 January, 2025)
• Disk diffusion - Slide show v 13.0 (1 January, 2025) 
• Disk diffusion - Reading guide v 11.0 (1 January, 2025)
• Anaerobic bacteria - disk diffusion methodology v 2.0 (2 January 2023). QC recommendations are now included in the general QC document.
• Anaerobic bacteria - disk diffusion reading guide v 2.0 (2 January 2023). Disk diffusion breakpoints for anaerobic bacteria are valid for FAA with 5% mechanically defibrinated horse blood as the only additive. 

For translations to other languages - contact National AST committees (NAC).

For previous versions of documents - see Previous versions.

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