ISO 6461-1 (1993) medium: DRCM

Media control Water quality 

Microorganisms and performance criteria for non-selective liquid media 'DRCM' used in Water quality  microbiology according to ISO 11133.

  • Qualitative control of Productivity

  • Best Practice DRCM

    Qualitative single tube method for performance testing of liquid media – pre-enrichment media

    1. Use a reference material or test suspension with a known number of Clostridium perfringens.
    2. Inoculate the media (DRCM) with 0.1 mL of more than 100 cfu/mL and less then 1000 cfu/mL of microorganisms.
    3. Incubate at (36 ± 1) °C for (44 ± 4) h.
    4. Asses the amount of growth as, 0 for no turbidity, 1 for slight turbidity or 2 for good turbidity.
    5. For this medium (DRCM) and standard (ISO 6461-1) combination the criteria is: "Turbidity (1–2)."

    Control strain WDCM number Incubation Criteria Characteristic reaction
    Clostridium perfringens (36 ± 1) °C for (44 ± 4) h
    anaerobic atmosphere
    Turbidity (1–2) Blackening
    The best practice for Qualitative control of Productivity for media control of 'DRCM' is based on the data displayed in this table according ISO 11133.
  • Qualitative control of Selectivity

  • Best Practice DRCM

    No further Best Practice available. For the correct method of testing see ISO 11133.

    Control strain WDCM number Ref. media Incubation Criteria Characteristic reaction
    Escherichia coli or (36 ± 1) °C for (44 ± 4) h
    anaerobic atmosphere
    Turbidity (0-1) No blackening
    The best practice for Qualitative control of Selectivity for media control of 'DRCM' is based on the data displayed in this table according ISO 11133.