Salmonella detection · Step 1 – pre-enrichment
Lactose Broth – pre-enrichment broth for Salmonella
Lactose Broth is a pre-enrichment broth used in Salmonella testing of foods according to the USA FDA Bacteriological Analytical Manual, and in the microbial examination of non-sterile pharmaceutical products. It gives injured Salmonella cells time to recover before selective enrichment.
- Pre-enrichment step of the FDA Salmonella method
- Used in USA FDA and EP methods
- Dehydrated powder, 500 g bottle · COLO code PRO7464
How Lactose Broth works
Peptone and beef extract supply nutrients without selective agents, so stressed Salmonella can repair and multiply. Lactose is fermented by coliforms with acid and gas, while Salmonella grows without fermenting it. After incubation, the broth is subcultured into selective enrichment broths.
Technical data
| Preparation | 13 g per litre of water; dispense (e.g. 225 mL per flask) and sterilise at 121 °C for 15 min |
| Final pH | 6.9 ± 0.2 |
| Incubation | 35–37 °C, 24 h |
| Storage | Dry, dark place; close the cap tightly after use |
| Shelf life | 3 years unopened |
Applications and practical notes
Lactose Broth is the pre-enrichment broth of the FDA BAM Chapter 5 method for many food types and is also used in pharmacopoeial testing. Typical applications include:
- dried foods, flour and spices
- eggs, egg products and confectionery
- non-sterile pharmaceutical products
- cosmetics and raw materials
Working with Lactose Broth: The sample is homogenised in Lactose Broth, typically 25 g in 225 mL, and the pH is checked before incubation. After pre-enrichment, portions are transferred to the selective enrichment broths.
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.
Lactose 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 Lactose Broth, please send us a request.
Where Lactose Broth fits 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 |
|---|---|---|
| Lactose Broth, dehydrated | PRO7464 | 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.
