Total viable count · Enumeration
Plate Count Agar – total aerobic count in food and water
Plate Count Agar (PCA, Standard Methods Agar) is the reference medium for the total count of aerobic micro-organisms in food and feed by the pour plate technique at 30 °C according to ISO 4833-1. It is also used for water, dairy products and surfaces.
- Medium of ISO 4833-1
- Pour plate or spread plate
- Non-selective total count
How Plate Count Agar works
Tryptone, yeast extract and glucose support the growth of most aerobic bacteria without selective agents, so the medium gives the total number of colony-forming units. Plates are prepared by the pour plate technique and colonies are counted after incubation.
Typical colony appearance
| Organism | Colonies |
| Escherichia coli, Bacillus subtilis | Grey-white colonies |
| Staphylococcus aureus | Yellow colonies |
Technical data
| Preparation | 23.5 g/L; boil to dissolve, dispense, autoclave 121 °C 15 min |
| Final pH | 7.0 ± 0.2 |
| Incubation | 30 °C, 72 h (ISO 4833-1) or 35–37 °C, 48 ± 2 h |
| Storage | Dry, dark place; keep the container tightly closed |
| Shelf life | 3 years |
Applications and practical notes
The total viable count is the basic hygiene indicator for food, feed, water and surfaces, determined for example according to ISO 4833-1. Typical applications include:
- Raw materials and finished food products
- Milk and dairy products
- Drinking and purified water
- Hygiene monitoring and shelf-life studies
Working with Plate Count Agar: Pour the plates with medium cooled to 44–47 °C, mix the inoculum well and count plates with 10–300 colonies.
Good practice with dehydrated media: keep the bottle tightly closed in a cool, dry place, weigh the powder quickly to avoid moisture uptake, and use fresh distilled or deionised water. Check the pH of each new batch after preparation and before use, and label prepared media with the date. Performance of each lot can be verified with reference strains according to ISO 11133, the standard for the preparation, production, storage and performance testing of culture media.
About total viable count methods: the total count of micro-organisms in food and feed is made by the pour plate technique on Plate Count Agar at 30 °C according to ISO 4833-1. Milk and dairy products are tested on milk plate count agar, and psychrotrophic bacteria at 6.5 °C for 10 days according to ISO 6730. Purified and pharmaceutical water is tested on low-nutrient R2A Agar. Each lot of medium is checked with reference strains according to ISO 11133. COLO.Science offers media and count plates for these methods.
Complete sets from one supplier: COLO.Science supplies culture media, supplements, rapid tests, identification kits and QC strains as complete sets for the method you follow. Send us your sample types and standards, and we will prepare an offer with the matching products and documentation.
Plate Count Agar is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include Plate Count Agar, please send us a request. With every delivery of Plate Count Agar you receive the lot number and expiry date, and on request we send the available documentation for Plate Count Agar.
Where Plate Count Agar fits in total viable count testing
- Food and feed – Plate Count Agar, pour plate at 30 °C
- Milk and dairy products – Milk Plate Count Agar; psychrotrophs at 6.5 °C
- Water – R2A Agar for purified water, Tryptone Glucose Extract Agar
- Fast results – aerobic count plates
See all total count products in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Plate Count Agar (PCA) | PRO7428 | 500 g |
Product notice: preparation, storage conditions and shelf life are given on the label. Technical data on this page are for orientation; the label and the lot documentation apply. B2B prices are quoted net, excluding VAT.
Sales and technical support
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Quotations and technical support for culture media and microbiology products across our international sales territory. B2B prices are net, excluding VAT.
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Need the complete set for your method?
Send the sample type, target organism and the standard you follow. COLO.Science will put together the media, supplements, QC strains and confirmation tests for the whole procedure.
