Listeria detection · media supplement
Listeria Enrichment Broth Supplement – for Tryptone Soya Yeast Extract Broth
Selective supplement that turns Tryptone Soya Yeast Extract Broth into a selective enrichment broth for Listeria. One vial completes 225 mL of broth.
- Selective supplement for Tryptone Soya Yeast Extract Broth
- Lyophilised, dissolved before use
- 10 vials per box · COLO code PRO7673
How the Listeria Enrichment Broth Supplement is used
The lyophilised supplement contains nalidixic acid and acriflavine. It is dissolved in sterile saline and added to the sterilised and cooled base; the antibiotics suppress Gram-negative and many Gram-positive accompanying bacteria.
Technical data
| Composition per vial | nalidixic acid 9.0 mg, acriflavine hydrochloride 3.375 mg |
| Use | Dissolve in 1 mL sterile saline and add to 225 mL of Tryptone Soya Yeast Extract Broth |
| Storage | 2–8 °C |
| Shelf life | 2 years |
Applications and practical notes
The supplement is used to prepare the selective enrichment broth for Listeria in food testing; the reference method ISO 11290-1 uses Half-Fraser and Fraser Broth. Typical applications include:
- ready-to-eat foods and delicatessen
- milk and dairy products
- fish and seafood
- environmental samples from food production
Working with Listeria Enrichment Broth Supplement: Dissolve the vial completely, add it only to the cooled sterile base and mix gently but thoroughly before dispensing or pouring. Keep unopened vials refrigerated.
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.
Listeria Enrichment 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 Listeria Enrichment Broth Supplement, please send us a request. With every delivery of Listeria Enrichment Broth Supplement you receive the lot number and expiry date, and on request we send the available documentation for Listeria Enrichment Broth Supplement.
Where the supplement fits in the Listeria workflow
- Primary enrichment – Half-Fraser Broth
- Secondary enrichment – Fraser Broth
- Selective isolation – chromogenic Listeria agar (Ottaviani-Agosti type) plus PALCAM or Oxford Agar
- Confirmation – subculture on TSYEA, biochemical identification and latex
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Listeria Enrichment Broth Supplement | PRO7673 | 10 vials |
| Tryptone Soya Yeast Extract Broth | PRO7506 | 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.
