Microorganisms and performance criteria for non-selective isolation media 'Nutrient agar' used in Food chain microbiology according to ISO 21528.
Qualitative control of Productivity
- Use a reference material or test suspension with a known number of Escherichia coli.
- The volume used for testing should contain 103 to 104 cfu for qualitative tests of plate media.
- Streak the test microorganism (Escherichia coli) on the media under test (Nutrient agar) to obtain discrete colonies.
- Incubate at (37 ± 1) °C for (24 ± 2) h.
- Asses the amount of growth as, 0 for no growth, 1 for weak growth or 2 for good growth.
- For this medium (Nutrient agar) and standard (ISO 21528) combination the criteria is: "Good growth (2)".
- The Characterictic reaction is: Growth.
Best Practice Nutrient agar
Qualitative control of Productivity solid medium
|Control strain||WDCM number||Incubation||Criteria||Characteristic reaction|
|Escherichia coli||(37 ± 1) °C for (24 ± 2) h||Good growth (2)||Growth|
|The best practice for Qualitative control of Productivity for media control of 'Nutrient agar' is based on the data displayed in this table according ISO 21528.|