Coliforms and E. coli · Enzyme substrate test for water
Multiple Enzyme Substrate Medium – defined substrate test for water
Multiple Enzyme Substrate Medium is a defined-substrate medium for water testing. It is dissolved in the sample or in sterile water, filter-sterilised and read by colour and fluorescence after incubation.
- Defined enzyme substrates
- Fluorescence under UV light
- Filter-sterilised, no autoclaving
How Multiple Enzyme Substrate Medium works
Target bacteria split specific enzyme substrates and release coloured or fluorescent products. Because only the target enzymes react, the result can be read without subculture.
Applications and practical notes
Membrane filtration and presence-absence media are used for coliforms and E. coli in drinking water, source water and bottled water. Typical applications include:
- Drinking water and source water monitoring
- Bottled water and ice testing
- Swimming pool and process water checks
- Laboratories working with membrane filtration
Working with Multiple Enzyme Substrate Medium: Prepare the medium with sterile filtration through 0.22 µm and check the result under a 366 nm UV lamp.
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 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.
Multiple Enzyme Substrate Medium is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include Multiple Enzyme Substrate Medium, please send us a request. With every delivery of Multiple Enzyme Substrate Medium you receive the lot number and expiry date, and on request we send the available documentation for Multiple Enzyme Substrate Medium.
Where Multiple Enzyme Substrate Medium fits in coliform and E. coli 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 |
|---|---|---|
| Multiple Enzyme Substrate Medium | PRO7595 | 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.
