Enterococci · Enumeration in water
Slanetz and Bartley Agar – membrane filtration of intestinal enterococci
Slanetz and Bartley Agar is the selective medium for the enumeration of intestinal enterococci in water by membrane filtration according to ISO 7899-2. It is also used for enterococci in food and other samples.
- Medium of ISO 7899-2
- Red, maroon or pink enterococci
- No autoclaving
How Slanetz and Bartley Agar works
Sodium azide inhibits Gram-negative bacteria. Enterococci reduce the colourless 2,3,5-triphenyltetrazolium chloride (TTC) in the medium to red formazan, so their colonies are red, maroon or pink. Typical colonies are confirmed on Bile Esculin Azide Agar.
Typical colony appearance
| Organism | Colonies |
| Enterococcus faecalis | Red, maroon or pink colonies |
| Escherichia coli, Staphylococcus aureus | Inhibited |
Technical data
| Preparation | 41.5 g/L; heat to boiling until dissolved; avoid prolonged heating and reboiling; do not autoclave; cool to about 50 °C and pour plates |
| Final pH | 7.2 ± 0.2 |
| Storage | Dry, dark place; keep the container tightly closed |
| Shelf life | 3 years |
Applications and practical notes
Enterococci and streptococci are tested in drinking, bathing and waste water, in food and in clinical and dairy laboratories, for example according to ISO 7899-2. Typical applications include:
- Drinking, bathing and recreational water
- Waste water and environmental samples
- Food and dairy products
- Clinical and veterinary microbiology
Working with Slanetz and Bartley Agar: Heat the medium only until it is dissolved, avoid prolonged heating and reboiling, and do not autoclave; the medium contains sodium azide.
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 the Enterococcus methods: intestinal enterococci are indicators of faecal contamination of water. ISO 7899-2 counts them by membrane filtration on Slanetz and Bartley Agar, where typical colonies are red, maroon or pink, and confirms them by transferring the membrane to Bile Esculin Azide Agar, where esculin hydrolysis turns the medium black. In food, enterococci are counted on bile esculin azide media. Streptococci are cultivated on blood agar, where the type of haemolysis is read, and grouped by Lancefield antigens. COLO.Science offers media, supplements, rapid tests and identification kits 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.
Slanetz and Bartley 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 Slanetz and Bartley Agar, please send us a request. With every delivery of Slanetz and Bartley Agar you receive the lot number and expiry date, and on request we send the available documentation for Slanetz and Bartley Agar.
Where Slanetz and Bartley Agar fits in Enterococcus and Streptococcus testing
- Enumeration in water – membrane filtration on Slanetz and Bartley Agar
- Confirmation – transfer of the membrane to Bile Esculin Azide Agar; Bile Esculin Agar for single colonies
- Streptococci – Blood Agar Base with blood for haemolysis, Mitis Salivarius Agar with potassium tellurite
- Identification – Lancefield grouping latex, qPCR or LAMP for Enterococcus faecalis
See all Enterococcus and Streptococcus products in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Slanetz and Bartley Agar | PRO7497 | 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.
