Pharmacopoeial media · Clostridia
Reinforced Clostridial Medium – enrichment of clostridia
Reinforced Clostridial Medium (RCM) is a rich medium for the cultivation and enrichment of clostridia and other anaerobes. In the pharmacopoeial test for Clostridia it is the enrichment step before subculture on Columbia Agar.
- Enrichment of clostridia and anaerobes
- Pharmacopoeial test for Clostridia
- Also for counts in food and water
How Reinforced Clostridial Medium works
Peptones, yeast extract and glucose provide nutrients, cysteine lowers the redox potential and a small amount of agar limits oxygen diffusion. Starch absorbs toxic metabolites, and sodium acetate supports clostridial growth.
Typical growth
| Organism | Growth |
| Clostridium sporogenes | Good growth, turbid broth |
Technical data
| Preparation | 38 g/L; boil until fully dissolved (contains starch), autoclave 121 °C 15 min |
| Final pH | 6.8 ± 0.2 |
| Incubation | 30–37 °C, anaerobic, 48 h |
| Storage | Dry, dark place; keep the container tightly closed |
| Shelf life | 3 years unopened |
Applications and practical notes
Tests for specified micro-organisms in non-sterile products, described in Ph. Eur. 2.6.13 and USP <62>, combine an enrichment in soya-bean casein digest broth with selective media for each organism and confirmation of typical colonies. Typical applications include:
- Raw materials and active ingredients
- Oral and topical non-sterile products
- Herbal products and food supplements
- Method suitability and growth promotion tests
Working with Reinforced Clostridial Medium: Boil the medium until the starch is fully dissolved before autoclaving, otherwise a slight white precipitate may form.
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 pharmacopoeial microbiological testing: the European Pharmacopoeia and the USP describe harmonised methods for non-sterile products – microbial enumeration (Ph. Eur. 2.6.12, USP <61>) and tests for specified micro-organisms (Ph. Eur. 2.6.13, USP <62>) – and the sterility test for sterile products (Ph. Eur. 2.6.1, USP <71>). The chapters define the media, incubation conditions and the growth promotion test that each batch of medium must pass with reference strains. COLO.Science offers the media, diluents, neutralisers and QC strains for these tests 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.
Reinforced Clostridial Medium is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include Reinforced Clostridial Medium, please send us a request. With every delivery of Reinforced Clostridial Medium you receive the lot number and expiry date, and on request we send the available documentation for Reinforced Clostridial Medium.
Where Reinforced Clostridial Medium fits in pharmacopoeial testing
- Sample preparation – Buffered Sodium Chloride-Peptone Solution, Tryptic Soy Broth and neutralising diluents
- Microbial enumeration – Tryptic Soy Agar (TAMC) and Sabouraud Dextrose Agar (TYMC)
- Specified micro-organisms – enrichment in Tryptic Soy Broth, then MacConkey, Mannitol Salt, Cetrimide, XLD, VRBG, RCM and Columbia media
- Sterility test – Fluid Thioglycollate Medium and Tryptic Soy Broth, 14 days
See all pharmacopoeial media in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Reinforced Clostridial Medium (RCM) | PRO7478 | 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.
