ISO 7251 (2005) method: Escherichia coli

Process control Food and animal feeding stuffs

Horizontal method for the detection and enumeration of presumptive Escherichia coli

  • Quantitative process control with RM-ECO.00012MM

  • Best Practice

    The single strain RM-ECO.00012MM is used for the detection and enumeration of coliforms

    1. Use a quantitative reference material (RM-ECO.00012MM) with a known number of Escherichia coli.
    2. Defrost the material at room temperature for 30 minutes.
    3. Mix well before use and dilute the material so countable numbers are inoculated on the media (EC).
    4. Best results are obtained when a practicable range of 80 cfu to 120 cfu per plate with a minimum number of 50 cfu per plate is used.
    5. Incubate at (44 ± 1) °C for (24 ± 2) h to (48 ± 2) h.
    6. Count the colony forming units and register in a control chart.
    7. The characteristic reaction is: Gas production and turbidity.

    Kind of reference material Biosisto product for this control method Control Strain WDCM number NCCB number
    Single-strain reference material Escherichia coli 00012 72002
    The Biosisto reference material in this table is used in the best practice for Quantitative process control according ISO 17025.