Shigella and Salmonella · Selective isolation
Desoxycholate Citrate Agar – isolation of Shigella and Salmonella
Desoxycholate Citrate Agar (DCA) is a selective and differential medium for the isolation of Shigella and Salmonella from food, water and faecal samples.
- For Shigella and Salmonella
- Lactose and neutral red indicator
- Gram-positive bacteria inhibited
How Desoxycholate Citrate Agar works
Sodium desoxycholate and citrate inhibit Gram-positive bacteria and many coliforms. Lactose fermenters form pink colonies, while Shigella and Salmonella do not ferment lactose and form colourless colonies; hydrogen sulphide producers have black centres.
Applications and practical notes
Shigella causes bacillary dysentery and is tested in food, water and clinical samples, for example according to ISO 21567. Typical applications include:
- Ready-to-eat foods, salads and vegetables
- Seafood and dairy products
- Drinking and surface water
- Clinical and public-health laboratories
Working with Desoxycholate Citrate Agar: Heat the medium only until it is dissolved, without autoclaving, and use the plates on the day of preparation.
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 Shigella and Yersinia methods: ISO 21567 describes the detection of Shigella in food by enrichment in Shigella broth with novobiocin, plating on selective agars such as MacConkey, XLD and Hektoen enteric agar, and biochemical and serological confirmation. ISO 10273 describes the detection of presumptive pathogenic Yersinia enterocolitica by enrichment at 25 °C and plating on CIN agar, followed by tests that separate pathogenic from non-pathogenic strains. COLO.Science offers media, supplements, rapid tests, identification kits and QC strains for these methods.
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.
Desoxycholate Citrate Agar is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include Desoxycholate Citrate Agar, please send us a request. With every delivery of Desoxycholate Citrate Agar you receive the lot number and expiry date, and on request we send the available documentation for Desoxycholate Citrate Agar.
Where Desoxycholate Citrate Agar fits in Shigella and Yersinia testing
- Enrichment – Shigella broth with selective supplement; for Yersinia a peptone-sorbitol-bile type broth
- Selective isolation – Chromogenic Shigella Agar, Desoxycholate Citrate Agar, XLD; for Yersinia CIN agar and Chromogenic Yersinia enterocolitica Agar
- Screening – qPCR or LAMP kits after enrichment
- Confirmation and QC – biochemical identification kits and reference strains
See all Shigella and Yersinia products in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Desoxycholate Citrate Agar | PRO7527 | 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.
