Part of Thermo Fisher Scientific

Thermo Scentific
 
 
 

Dehydrated Culture Media

STANDARD PLATE COUNT AGAR (APHA)

Code: CM0463

A standard medium corresponding to the APHA formulation for milk, water, food and dairy products.

Typical Formula*

gm/litre

Yeast extract

2.5

Pancreatic digest of casein

5.0

Glucose

1.0

Agar

15.0

pH 7.0 ± 0.2 @ 25°C

 
* Adjusted as required to meet performance standards

Directions
Suspend 23.5g in 1 litre of distilled water. Bring to the boil to dissolve completely. Dispense into bottles and sterilise by autoclaving at 121°C for 15 minutes.

Description
Standard Plate Count Agar was developed by Buchbinder et al.1 who wished to use an agar without milk solids in the formulation and investigated the control tests necessary to give standard results in dairy products with statistically valid counts.

Standard Plate Count Agar meets the formulation of the APHA2, AOAC3 and PHLS4 .

The quality control of Standard Plate Count Agar (APHA) includes testing in accordance with ISO 11133:20145.

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*
WDCM 00003

Good growth; straw coloured colonies

Staphylococcus aureus® ATCC 25923*
WDCM00034
Good growth; straw coloured colonies

Negative control:

 

Uninoculated medium

No change

* This organism is available as a Culti-Loop®

Precautions
When carrying out prescribed Standard Methods it is essential to follow the protocols given in precise detail.

References
1.
Buchbinder et al. (1951) Public Health Reports. 66. 327-329.
2. American Public Health Association (1976) Compendium of Methods for the Microbiological Examination of Foods. APHA Inc. Washington DC.
3. Association of Official Analytical Chemists (1995) Bacteriological Analytical Manual. 8th Edn. AOAC. Washington DC.
4. PHLS Standard Methods for the Microbiological Examination of Food and Dairy Samples (1999) Aerobic plate count at 30°C F10 and F11.
5. International Organization for Standardization. ISO 11133:2014 Microbiology of food, animal feed and water - Preparation, production, storage and performance testing of culture media

 
©2001 - 2021 Oxoid Limited, All rights reserved.
Copyright, Disclaimer and Privacy Policy | Conditions of Sale | About Us | Cookies
Thermo Fisher Scientific Inc.