Listeria detection · enrichment and culture
Tryptone Soya Yeast Extract Broth – nutrient broth for Listeria
Tryptone Soya Yeast Extract Broth (TSYEB, TSB-YE) is a nutrient-rich broth for the cultivation of Listeria. With the Listeria Enrichment Broth Supplement it becomes a selective enrichment broth; without supplement it is used to grow pure cultures for confirmation tests.
- Nutrient broth for Listeria cultures
- Selective enrichment with Listeria Enrichment Broth Supplement
- Dehydrated powder, 500 g bottle · COLO code PRO7506
How Tryptone Soya Yeast Extract Broth works
Tryptone, soya peptone and yeast extract supply nutrients and vitamins for fast growth of Listeria. Dipotassium phosphate buffers the medium. When nalidixic acid and acriflavine are added as supplement, accompanying bacteria are suppressed.
Technical data
| Preparation | 36 g per litre of water; boil to dissolve and sterilise at 121 °C for 15 min; for enrichment add one vial of Listeria Enrichment Broth Supplement per 225 mL at about 50 °C |
| Final pH | 7.2 ± 0.2 |
| Incubation | 36 ± 1 °C, 24 h (as enrichment broth 30 ± 1 °C, 24 h) |
| Storage | Dry, dark place; close the cap tightly after use |
| Shelf life | 3 years unopened |
Applications and practical notes
Tryptone Soya Yeast Extract Broth is used for Listeria cultures in food and environmental testing, as described in ISO 11290-1. Typical applications include:
- enrichment of Listeria with selective supplement
- growth of pure cultures for confirmation tests
- preparation of inocula for media testing
- environmental monitoring samples
Working with Tryptone Soya Yeast Extract Broth: Add the selective supplement only to the cooled base. For confirmation tests, use the broth without supplement and inoculate it with a single, well-isolated colony.
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 Listeria culture method: the reference method for Listeria monocytogenes in the food chain, ISO 11290-1, uses primary enrichment in Half-Fraser Broth, secondary enrichment in Fraser Broth, plating on a chromogenic agar of the Ottaviani-Agosti type and a second selective agar, and confirmation of typical colonies. The FDA BAM Chapter 10 uses Buffered Listeria Enrichment Broth instead. 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.
Tryptone Soya Yeast Extract Broth is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include Tryptone Soya Yeast Extract Broth, please send us a request. With every delivery of Tryptone Soya Yeast Extract Broth you receive the lot number and expiry date, and on request we send the available documentation for Tryptone Soya Yeast Extract Broth.
Where Tryptone Soya Yeast Extract Broth 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 |
|---|---|---|
| Tryptone Soya Yeast Extract Broth | PRO7506 | 500 g |
| Listeria Enrichment Broth Supplement | PRO7673 | 10 vials |
| Tryptone Soya Yeast Extract Agar | PRO7502 | 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
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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.
