Listeria detection · selective enrichment
Listeria Enrichment Broth Base, granulated – LB1 and LB2 enrichment
Granulated Listeria Enrichment Broth Base for the two-step selective enrichment of Listeria monocytogenes (LB1 and LB2). The base is completed with the LB1 or LB2 supplement. Granulated media are low in dust and dissolve quickly.
- Base for LB1 and LB2 enrichment broths
- Granulated, low-dust form
- Granules, 250 g bottle · COLO code PRO7630
How Listeria Enrichment Broth works
The nutrient-rich base supports the growth of Listeria. Nalidixic acid and acriflavine, added with the LB1 or LB2 supplement, suppress Gram-negative and Gram-positive accompanying bacteria; LB2 has a higher acriflavine concentration for the second step.
Technical data
| Preparation | 49.4 g per litre of water; boil to dissolve, sterilise at 121 °C for 15 min, cool to about 45 °C; add LB1 supplement (1 vial per 225 mL) or LB2 supplement (1 vial per 200 mL) |
| Final pH | 7.2 ± 0.2 |
| Incubation | 30 ± 1 °C, 24 h |
| Storage | Dry, dark place; close the cap tightly after use |
| Shelf life | 3 years unopened |
Applications and practical notes
Listeria Enrichment Broth is used for the two-step enrichment of Listeria monocytogenes in national food methods; the reference method ISO 11290-1 uses Half-Fraser and Fraser Broth. Typical applications include:
- ready-to-eat foods, cooked meat products and delicatessen
- milk, cheese and other dairy products
- fish, seafood and smoked fish
- environmental swabs from food production areas
Working with Listeria Enrichment Broth: Add the LB1 or LB2 supplement only to the base cooled to about 45 °C, and use the right supplement for each step, because they contain different amounts of acriflavine.
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 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 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, please send us a request. With every delivery of Listeria Enrichment Broth you receive the lot number and expiry date, and on request we send the available documentation for Listeria Enrichment Broth.
Where Listeria Enrichment Broth fits in the workflow
- First enrichment – LB1 (base + LB1 supplement)
- Second enrichment – LB2 (base + LB2 supplement)
- Selective isolation – chromogenic Listeria agar plus PALCAM or Oxford Agar
- Confirmation – subculture on TSYEA, biochemical identification and latex
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Listeria Enrichment Broth Base, granulated | PRO7630 | 250 g |
| Listeria Enrichment Broth (LB1) Supplement, for 225 mL | PRO7674 | 10 vials |
| Listeria Enrichment Broth (LB2) Supplement | PRO7675 | 10 vials |
| Listeria Enrichment Broth (LB1) Supplement, for 2.25 L | PRO7691 | 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
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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.
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.
