Yeasts · Assimilation base
Yeast Nitrogen Base with Amino Acids – base for carbon assimilation tests
Yeast Nitrogen Base with Amino Acids contains nitrogen, vitamins, trace elements and amino acids, but no carbon source. A carbohydrate is added as needed, so the base is used for carbon assimilation tests in yeast identification and for defined yeast cultures.
- No carbon source – add the test carbohydrate
- For yeast identification and defined culture
- Filter-sterilised, not autoclaved
How Yeast Nitrogen Base with Amino Acids works
A 10× stock is prepared with the carbohydrate to be tested, filter-sterilised and diluted with sterile water. Growth of the yeast shows that it can use the carbon source, which is one of the classic tests for yeast identification.
Typical reactions
| Organism | Growth |
| Saccharomyces cerevisiae | Growth (turbidity) with glucose |
Technical data
| Preparation | 10× stock: 6.7 g with 5 g glucose (or another carbon source) in 100 mL, warm gently and filter-sterilise (no autoclaving); dilute 1 + 9 with sterile water |
| Final pH | 5.4 ± 0.2 |
| Incubation | 30 ± 2 °C, 48 h |
| Storage | Dry, dark place; keep the container tightly closed |
| Shelf life | 3 years unopened |
Applications and practical notes
Selective and identification media for Candida species are used in clinical, pharmaceutical and research laboratories to recognise Candida albicans and other yeasts. Typical applications include:
- Recognition of Candida albicans in mixed cultures
- Differentiation of Candida species
- Pharmaceutical and clinical-environmental samples
- Research and teaching
Working with Yeast Nitrogen Base with Amino Acids: Prepare the stock solution with filter sterilisation, because autoclaving damages the vitamins.
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 yeast and mould methods: in the food chain, yeasts and moulds are counted by spread plating on DRBC Agar for products with a water activity above 0.95 according to ISO 21527-1, and on DG18 Agar for drier products according to ISO 21527-2. The FDA BAM Chapter 18 describes similar plate count methods. In pharmaceutical microbiology, the total yeast and mould count (TYMC) and the test for Candida albicans use Sabouraud media according to EP 2.6.12 / 2.6.13 and USP <61> / <62>. COLO.Science offers counting media, identification media, supplements and reference strains for every step.
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 Nitrogen Base with Amino Acids 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 Nitrogen Base with Amino Acids, please send us a request. With every delivery of Yeast Nitrogen Base with Amino Acids you receive the lot number and expiry date, and on request we send the available documentation for Yeast Nitrogen Base with Amino Acids.
Where Yeast Nitrogen Base with Amino Acids fits in yeast and mould testing
- Food and feed counts – DRBC Agar for aw > 0.95 (ISO 21527-1) and DG18 Agar for aw ≤ 0.95 (ISO 21527-2); alternatives: Rose Bengal Chloramphenicol, PDA with chloramphenicol, YGC for dairy products
- Pharmaceutical products – Sabouraud Dextrose Agar and Broth for TYMC and the Candida albicans test (EP 2.6.12 / 2.6.13, USP <61> / <62>)
- Cultivation and identification – PDA, Malt Extract and Czapek-Dox Agar for moulds; Corn Meal, chromogenic Candida and BIGGY Agar, Yeast Nitrogen Base for yeasts
- Fermentation and QC – WL Nutrient, Wort Agar and YPD for brewing and culture yeasts; C. albicans and A. brasiliensis reference strains for media testing
See the complete yeast and mould set in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Yeast Nitrogen Base with Amino Acids | PRO7546 | 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.
