Part of Thermo Fisher Scientific
MILK PLATE COUNT AGAR
PLATE COUNT AGAR WITH ANTIBIOTIC FREE SKIM MILK
Code: CM0681
A medium for the enumeration of viable organisms in milk and dairy products.
Typical Formula* |
gm/litre |
Tryptone |
5.0 |
Yeast extract |
2.5 |
Glucose |
1.0 |
Antibiotic free skim milk |
1.0 |
Agar |
10.0 |
pH 6.9 ± 0.1 @ 25°C |
Directions
Suspend 19.5g in 1 litre of distilled water. Bring to the boil with frequent agitation, mix and distribute into final containers. Sterilise by autoclaving at 121°C for 15 minutes.
Description
Plate Count Agar with Antibiotic Free Skim Milk is equivalent to the medium recommended by British Standards Institution1 and International Organization for Standardization2. The medium is used for the enumeration of viable organisms in milk and dairy products.
The quality control of Milk Plate Count Agar includes testing in accordance with ISO 11133:20143.
Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared plates at 2-8°C.
Appearance
Dehydrated medium: Straw coloured, free-flowing powder
Prepared medium: Straw coloured gel
Quality control
Positive controls: |
Expected results |
Escherichia coli ATCC® 25922* WDCM00013 |
Good growth; straw coloured colonies |
Bacillus subtilis ATCC® 6633* WDCM00003 |
Good growth; straw coloured colonies |
Staphylococcus aureus® ATCC 25923* WDCM00034 |
Good growth; straw coloured colonies |
Negative control: |
|
Uninoculated medium |
No change |
Compare with previous lot/batch using pasteurised and raw milk samples, incubated at 32-35°C for 48 hours.
Precautions
Ensure that the procedures and media used in milk product testing comply with the National Regulations required for each country. Refer to any appropriate standards or methods for the correct technique, time and temperature of incubation.
References
1. British Standards Institution BS4285 Section 1.2 1984.
2.International Organization for Standardization. ISO 4833 Parts 1 and 2 Microbiology of the food chain - Horizontal method for the enumeration of microorganisms
3. International Organization for Standardization. ISO 11133:2014 Microbiology of food, animal feed and water - Preparation, production, storage and performance testing of culture media