Salmonella detection · Step 2 – supplement for tetrathionate broths
Tetrathionate / MKTTn Broth Supplement
Two-component supplement (iodine–iodide solution and brilliant green solution) for completing tetrathionate broth base or MKTTn broth base before use, for the selective enrichment of Salmonella.
- For tetrathionate and MKTTn broth bases
- Iodine–iodide and brilliant green solutions
- Box of 2 × 5 vials · COLO code PRO7668
How the supplement is used
Iodine reacts with thiosulfate in the base to form tetrathionate, which Salmonella reduces while most coliforms are inhibited; brilliant green suppresses Gram-positive bacteria. Both solutions are added aseptically to the cooled base just before use.
Technical data
| Use | 1 vial of iodine solution and 1 vial of brilliant green solution per 100 mL of base |
| Storage | 2–8 °C; after opening keep in the box, protected from light |
| Shelf life | 3 years |
Applications and practical notes
This supplement completes tetrathionate and MKTTn broth bases used in ISO 6579-1 and FDA BAM Chapter 5. Typical applications include:
- meat, poultry, eggs and egg products
- milk, dairy products and infant formula
- feed, spices and dry foods
- environmental swabs from the food production area
Working with Tetrathionate / MKTTn Broth Supplement: Add both solutions only to the cooled base and mix well before dispensing. The complete broth should be used on the day of preparation and should not be heated again.
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 the Salmonella culture method: the reference method for Salmonella in the food chain, ISO 6579-1, has four steps: non-selective pre-enrichment, selective enrichment in two broths, plating on two selective agars and confirmation of typical colonies. The FDA BAM Chapter 5 follows the same principle with media adapted to different food types. Rapid tests and identification kits shorten the time to result, but positive screening results are usually confirmed by the culture method. COLO.Science offers products for every step, so that one supplier covers the whole procedure.
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.
Tetrathionate / MKTTn Broth 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 Tetrathionate / MKTTn Broth Supplement, please send us a request. With every delivery of Tetrathionate / MKTTn Broth Supplement you receive the lot number and expiry date, and on request we send the available documentation for Tetrathionate / MKTTn Broth Supplement. If you are changing to Tetrathionate / MKTTn Broth Supplement from another supplier, we are happy to advise on the transition.
Where tetrathionate broths fit in the Salmonella workflow
- Pre-enrichment – Buffered Peptone Water or Lactose Broth
- Selective enrichment – RVS Broth and MKTTn Broth
- Selective isolation – XLD Agar plus a second selective or chromogenic agar
- Confirmation – TSI, Lysine Iron Agar, Urea Agar, latex and biochemical identification
See the complete Salmonella set in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Tetrathionate / MKTTn Broth Supplement | PRO7668 | 2 × 5 vials |
| MKTTn Broth Base, dehydrated | PRO7438 | 500 g |
| Fluid Tetrathionate Medium, dehydrated | PRO7483 | 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
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.
