Water · Colony count
Yeast Extract Agar – culturable micro-organisms in water
Yeast Extract Agar is a nutrient agar for the count of culturable bacteria, yeasts and moulds in water by the pour plate technique.
- Colony count in water
- Pour plate technique
- Bacteria, yeasts and moulds
How Yeast Extract Agar works
Yeast extract and peptone support a wide range of water micro-organisms. Colony counts after incubation at two temperatures show the general bacterial load and the quality of the water treatment.
Technical data
| Storage | Cool, dry place away from bright light; keep the container tightly closed |
| Shelf life | 3 years |
Applications and practical notes
The colony count of culturable micro-organisms is the basic indicator of water quality and hygiene. Typical applications include:
- Drinking water and bottled water
- Water treatment and distribution systems
- Process and cooling water
- Hygiene monitoring
Working with Yeast Extract Agar: Pour the plates with medium cooled to 44–47 °C and incubate parallel plates at the temperatures required by your method.
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.
Yeast Extract 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 Yeast Extract Agar, please send us a request. With every delivery of Yeast Extract Agar you receive the lot number and expiry date, and on request we send the available documentation for Yeast Extract Agar.
Where Yeast Extract 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 |
|---|---|---|
| Yeast Extract Agar | PRO8185 | 250 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
COLO LabExperts
Polje ob Sotli 4, SI-3255, Slovenia
Quotations and technical support for culture media and microbiology products across our international sales territory. B2B prices are net, excluding VAT.
COLO.SCIENCE | MICROBIOLOGY SUPPORT
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.
