Product overview
Liofilchem CHRISTENSEN Urea Agar 200 mL Culture Media 412100 is a Liofilchem microbiology product supplied by Kormay Biomedicals. Its practical role is differential medium used for determining urease activity and for identification of organisms from clinical specimens and other samples. The medium complies with the requirements of the standards ISO 6579-1, ISO 10273, ISO 19250, ISO 21567 and ISO 11133. This medium is intended as an aid in the diagnosis, requiring further tests to complete the diagnostic results.
This product belongs in fungal or yeast workflows where recovery, differentiation, or susceptibility testing depends on controlled media, incubation, and disciplined result reading.
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Where this product fits
This product is most useful when spoilage organisms or yeasts need controlled recovery and readable morphology. The lab should define incubation conditions, what counts as typical growth, and how suspect isolates are confirmed before the result is used for shelf-life or investigation decisions.
Result signals and confirmation
At the end of the incubation period observe the color of the medium. A pink color indicates a positive reaction (urease activity), while no color change, with the medium remaining yellow to orange, indicates a negative reaction. Proteus spp. usually complete the reaction in 4-5 hours and therefore can be easily differentiated from weaker urease- producing organisms such as Klebsiella and Enterobacter spp. Typical Salmonella cultures do not hydrolyze urea so that the color of the medium will remain unchanged. Some pathogenic Y.
Method principle
Peptone provides nitrogen, carbon, and amino acids required for microbial growth. Glucose serves as an energy source. Sodium chloride maintains the osmotic balance of the medium. Monopotassium phosphate acts as a buffer. Phenol red is the pH indicator, and agar is the solidifying agent. Urea is included as a substrate for the urease enzyme. Microorganisms producing urease hydrolyze urea into ammonia and carbon dioxide. The release of ammonia increases the pH of the medium, shifting it toward alkaline conditions. This change is detected by the phenol red indicator, which turns from yellow/orange to pink/red.
Bench workflow
- Preparation: Dehydrated medium Suspend 24.0 g of the powder in 1 liter of distilled or deionized water. Mix well. Heat until completely dissolved. Sterilize in autoclave at 121°C for 15 minutes. Cool to 45-50°C. Aseptically add 50 ml of Urea 40% supplement. Mix well and pour into sterile final containers. Medium in bottles Melt the content of the bottle in a water bath at 100°C (with the cap partially removed) until completely dissolved. Then screw the cap and check the homogeneity of the dissolved medium, if it is the case turning the bottle upside down. Cool at 45-50°C.
- Materials required: Standard microbiological supplies and equipment such as: autoclave, sterile Petri plates, test tubes, inoculating loops, swabs, incubator,
- Procedure: Use a heavy inoculum from a pure 18–24-hour culture. Inoculate by streaking over the slant surface. Incubate at 37 ± 1°C for up to 24 hours under aerobic atmosphere (slightly loosen caps). Observe reactions after 6 and 24 hours. Longer periods of incubation may be necessary.
Controls and performance checks
- Formula / composition: * (g/litre) Base medium Peptone 1.0 Glucose 1.0 Sodium Chloride 5.0 Monopotassium Phosphate 2.0 Phenol Red 0.012 Agar 15.0 Final pH 6.8 ± 0.2 *Adjusted and/or supplemented as required to meet
- Quality control: organisms. © Liofilchem - Christensen Urea Agar - Rev.0 / 27.03.2026 Page 2 of 17 SPECIMENS Clinical specimens should be sampled at the acute stage, before antimicrobial therapy (where possible) and examined as soon as possible after collection. Good laboratory practices for collection, transport and
- Performance: specifications. Prepared medium Base Supplement Urea Agar Base (Christensen) + Urea 40 % Supplement
Storage, limits, and safety
- Limitations: Invalid results can be caused by poor specimen quality, improper sample collection, improper transportation, improper laboratory processing, or a limitation of the testing technology. The operator should understand the principles of the procedures, including its
- Warnings / precautions: 1) For in vitro diagnostic use (IVD). 2) For laboratory professional use only. 3) Operators must be trained and have certain experience. Please read the instructions carefully before using the product. Reliability of assay results cannot be guaranteed if there are any deviations from the instructions in this document. 4) Consult the Safety Data Sheet (SDS) for information regarding hazards and safe handling practices. 5) Do not use if the product or packaging appears to be damaged. 6) Follow standard
- Storage / shelf life: of the clinical specimens should be applied. Refer to specific guidelines for more information about specimen collection and
- Waste disposal: of waste must be carried out according to national and local regulations in force.
Safety and documentation points
- Hazards: 2.1 Classification of the substance or mixture This product does not meet the criteria for classification in any hazard class in accordance to Regulation (EC) No. 1272/2008. concerning the classification, labelling and packaging of substances and mixtures. 2.2 Label elements The product does not need to be labeled in accordance with EC directives or respective national laws. 2.3 Other hazards - none 3. COMPOSITION / INFORMATION ON INGREDIENTS Refer to component MSDS 4.
- Exposure controls: Refer to component MSDS 9. PHYSICAL AND CHEMICAL PROPERTIES Refer to component MSDS 10. STABILITY AND REACTIVITY Refer to component MSDS SAFETY DATA SHEET (According to Regulation EC n ° 1907/2006) Revision: 2 / Revision Date: 01.06.201 5 Liofilchem s.r.l. Via Scozia - Zona Industriale 64026, Roseto degli Abruzzi (TE) Italy - Tel +39 0858930745 - Fax +39 0858930330 MSDS Ref. 412100 Page 2 of 3 11. TOXICOLOGICAL INFORMATION Refer to component MSDS 12.
- Disposal: Refer to component MSDS 14. INFORMAZIONI SUL TRASPORTO 14.1 UN number ADR/RID: - IMDG: - IATA: - 14.2 UN proper shipping name ADR/RID: Not dangerous goods IMDG: Not dangerous goods IATA: Not dangerous goods 14.3 Transport hazard class(es) ADR/RID: - IMDG: - IATA: - 14.4 Packaging group ADR/RID: - IMDG: - IATA: - 14.5 Environmental hazards ADR/RID: no IMDG: no IATA: no 14.6 Special
Ordering and documentation checks
- Kormay SKU: KB74412100
- Catalog/document code matched: 412100, 2026
Before ordering, confirm the current IFU, SDS/MSDS, batch QC certificate or COA requirements, storage temperature, shelf life after receipt, and whether your SOP needs method verification before routine use.
Order / request documentation: https://www.kormay.ca/products/christensen-urea-agar-200-ml-for-microbiology-lab-testing