Raw material · Protein
Casein – raw material for culture media
Casein – casein is the main milk protein, used in media that test proteolysis, for example skim milk and casein agars.
- Milk protein
- For proteolysis test media
- 500 g pack
How Casein works
Proteolytic micro-organisms hydrolyse casein and form clear zones in casein-containing agar.
Use in the laboratory: this milk protein is used to prepare milk agar, skim milk agar and similar media for the detection of proteolytic bacteria such as Bacillus, Pseudomonas and spoilage organisms in milk and dairy products. The protein does not dissolve in neutral water, so it is first dissolved in a slightly alkaline solution and then added to the agar base. Clear zones around colonies show that the protein has been hydrolysed. COLO.Science supplies it together with the agar, peptones and extracts needed for these media.
Storage and handling of raw materials: keep the container tightly closed in a cool, dry place and protect it from moisture, because protein powders absorb water and form lumps. Weigh the required amount quickly with a clean, dry spatula, record the lot number and the date of opening, and use the oldest lot first. For accredited laboratories, the suitability of every new lot is confirmed in the final medium with reference strains before routine use, and the result is kept with the media preparation records.
Applications and practical notes
Raw materials are used to prepare culture media in-house, to modify standard formulations and in fermentation and bioprocess media. Typical applications include:
- Preparation of culture media from single components
- Fermentation and bioprocess media
- Research and method development
- Production of media in larger volumes
Working with Casein: Disperse casein in slightly alkaline water before heating.
Good practice with media and supplements: 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 culture media raw materials: the performance of a culture medium depends on the quality and consistency of its ingredients – peptones and extracts provide nitrogen, vitamins and growth factors, agar the gel, and bile salts or deoxycholate the selectivity. Laboratories that prepare their own media, and producers of media and fermentation broths, verify each new lot of raw material with reference strains according to ISO 11133. COLO.Science supplies raw materials in laboratory and bulk packs together with ready-made dehydrated media.
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.
Casein is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include Casein, please send us a request. With every delivery of Casein you receive the lot number and expiry date, and on request we send the available documentation for Casein.
Where Casein fits in culture media preparation
- Gelling agents – bacteriological, reagent and technical grade agar
- Nitrogen sources – peptones, tryptone, soy peptone, proteose peptone, polypeptone and casein hydrolysates
- Growth factors – yeast extract, beef extract and malt extract
- Selective and special components – bile salts, sodium deoxycholate, soy lecithin, casein and lactose
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Casein | PRO7784 | 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.
