E. coli O157 · Supplement
Potassium Tellurite Supplement – selective supplement for O157 agar
Potassium Tellurite Supplement is the selective supplement for Chromogenic E. coli O157 Agar. Tellurite inhibits many bacteria of the background flora, while E. coli O157 tolerates it.
- Selective supplement for O157 agar
- Liquid, ready to add
- 1 mL vials
How Potassium Tellurite Supplement works
Potassium tellurite is toxic for many Gram-negative and Gram-positive bacteria. E. coli O157:H7 is usually tellurite resistant, so the supplement increases the selectivity of the O157 medium.
Applications and practical notes
E. coli O157 and other Shiga toxin-producing E. coli (STEC) are tested in meat, raw milk products, sprouts and vegetables, for example according to ISO 16654 and FDA BAM Chapter 4. Typical applications include:
- Raw and minced meat, especially beef
- Raw milk and raw-milk cheese
- Sprouts, leafy greens and other fresh produce
- Outbreak investigations and environmental samples
Working with Potassium Tellurite Supplement: Add the supplement only to base cooled to about 50 °C and mix gently to avoid air bubbles.
Good practice with media and supplements: 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 coliform and E. coli methods: coliforms and E. coli are counted either by the multiple-tube (MPN) method, with a presumptive broth followed by confirmation broths, or by colony counts on selective agars. FDA BAM Chapter 4 describes both approaches for food and water, and ISO 16649-2 gives the colony-count method for β-glucuronidase-positive E. coli on TBX Agar. E. coli O157 and other STEC need dedicated media, serology and PCR. COLO.Science offers media, supplements, rapid tests, identification kits and QC 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.
Potassium Tellurite Supplement is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include Potassium Tellurite Supplement, please send us a request. With every delivery of Potassium Tellurite Supplement you receive the lot number and expiry date, and on request we send the available documentation for Potassium Tellurite Supplement.
Where Potassium Tellurite Supplement fits in E. coli O157 testing
- Presumptive test – Lauryl Sulfate Tryptose Broth (MPN) or VRBL / chromogenic agar (colony count)
- Confirmation – BGLB Broth for coliforms; EC or EC-MUG Broth at 44.5 °C for E. coli
- Isolation – EMB, MacConkey, TBX or chromogenic E. coli agar
- Identification – IMViC kit; for O157 and STEC: SMAC or chromogenic O157 agar, latex and PCR
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Potassium Tellurite Supplement for E. coli O157 Agar | PRO7684 | 10 vials |
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
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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.
