Urine culture · Chromogenic agar
Chromogenic UTI Agar – colour differentiation of urinary bacteria
Chromogenic UTI Agar is a differential medium for urine culture. Chromogenic substrates give the most common urinary bacteria different colony colours, so E. coli, enterococci and coliform groups can be told apart directly on the plate.
- Different colours for common urinary bacteria
- E. coli without extra tests
- Colony count and differentiation on one plate
How Chromogenic UTI Agar works
Two chromogenic substrates are split by β-galactosidase and β-glucosidase. E. coli forms purple-red colonies, enterococci blue-green colonies and Klebsiella, Enterobacter and Citrobacter metallic blue colonies.
Typical colony appearance
| Organism | Colonies |
| Escherichia coli | Purple-red colonies |
| Enterococcus faecalis | Small blue-green colonies |
| Citrobacter freundii | Metallic blue colonies with a red halo |
Technical data
| Preparation | 33 g/L; boil until dissolved, autoclave 121 °C 15 min, cool to about 50 °C and pour plates |
| Final pH | 7.0 ± 0.2 |
| Incubation | 36 ± 1 °C, 18–24 h |
| Storage | Powder 2–30 °C, dry and dark; prepared plates 2–8 °C, up to 1 week |
Applications and practical notes
Electrolyte-deficient and chromogenic media are used for the culture and colony count of urine samples and for the differentiation of the common Gram-negative and Gram-positive bacteria found in them. Typical applications include:
- Colony count of urine samples
- Differentiation of urinary bacteria
- Prevention of Proteus swarming
- Microbiology laboratories
Working with Chromogenic UTI Agar: Protect the plates from light and read them after 18–24 hours, because colours can change on prolonged incubation.
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 general-purpose media: general-purpose media are not tied to one reference method. They are used in every laboratory for cultivation, revival of reference strains, purity checks and as bases for enriched and test media. Their performance is verified with reference strains according to ISO 11133, and media for susceptibility testing follow the requirements of EUCAST and CLSI. COLO.Science offers general media, enriched bases, supplements and QC strains from one source.
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.
Chromogenic UTI 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 Chromogenic UTI Agar, please send us a request. With every delivery of Chromogenic UTI Agar you receive the lot number and expiry date, and on request we send the available documentation for Chromogenic UTI Agar.
Where Chromogenic UTI Agar fits in general microbiology
- Sample preparation – Peptone Water, Phosphate Buffer and other diluents
- Cultivation and revival – Nutrient, BHI and Columbia media
- Fastidious organisms – blood, chocolate and GC media with supplements
- Testing and identification – Mueller Hinton for susceptibility, CLED and chromogenic agar for urine, biochemical tests
See all general-purpose media in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Chromogenic UTI Agar | PRO7597 | 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.
