Laboratory use profile
Liofilchem TOS Propionate Agar Base Culture Media 610378 is a Liofilchem microbiology product supplied by Kormay Biomedicals. Its practical role is tOS Propionate Agar Base is a selective medium used with supplements for the enumeration of bifidobacteria in milk products includingfermented and non-fermented milks, milk powders and infant formulae. This medium complies with the specification given by ISO 29981/IDF 220.
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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Use case and sample types
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.
Decision criteria after incubation
Observe colonies growth. Typically, bifidobacteria grow as white colonies of 1-4 mm diameter sizes. Count colonies on all plates containing 15-300 colonies. Report the count as CFU per ml of sample allowing for dilution factors.
Method logic
Casein peptone provides the nitrogen, vitamins, minerals and amino acids for bacterial growth. Yeast extract is a source of vitamins, particularly of B-group. Galactoligosaccharide TOS is a growth factor specific for bifidobacteria. Phosphates act as buffer. Magnesium sulfate allows the recovery of preinjured bifidobacteria. Ammonium sulfate serves as nitrogen source. L-cysteine is a reducing agent. Sodium Propionate is the selective agent inhibiting the accompanying flora. Agar is the solidifying agent.Supplementation with Lithium-Mupirocin (MUP), contained in MUP Selective Supplement (ref. 81101), confers further selectivity against lactobacilli, lactococci, streptococci and leuconostocs. Mupirocin is so highly selective that in most cases only bifidobacteria grow with visible colonies with no need for confirmation.
Preparation and execution notes
- Preparation: Suspended 62.5 g of powder in 1 liter of distilled or deionized water. Heat to boiling to dissolve completely. DO NOT OVERHEAT. Sterilize by autoclaving at 115 ± 3°C for 15 minutes. Cool the medium to 45-50°C before adding the rehydrated content of 2 vials (10 ml)of MUP Selective Supplement.
- Procedure: Use 1/4 strength Ringer's solution (ref. 81059) to prepare the initial sample suspension and further decimal dilutions. Inoculate the completed TOS-MUP medium by the pour-plate method or by spreading the sample over the agar surface. NOTE: Bifidobacteria are sensitive to oxygen from air, so time from the first dilution to the agar inoculation should not exceed 15 minutes. Incubate anaerobically at 37°C for 72 ± 3 hours.
Formula, QC, and performance
- Formula / composition: (g/l)Casein Peptone10.0Yeast Extract 1.0Galactoligosaccharide TOS10.0Dipotassium Phosphate 4.8Monopotassium Phosphate 3.0Magnesium Sulfate, heptahydrated 0.2Ammonium Sulfate 3.0L-Cysteine HCl 0.5Sodium Propionate15.0Agar15.0Final pH 6.7 ± 0.2 at 25°C
- Quality control: 1.Control of general characteristics, label and print2.Microbiological controlInoculum for productivity: 50-100 CFUInoculum for selectivity: 103-104 CFUIncubation conditions: 72 ± 3 h at 37 ± 1°C under anaerobic atmosphereMicroorganismGrowthColony ColourBifidobacterium animalis subsp. animalisATCC 25527GoodWhiteBifidobacterium animalis subsp.
Risk controls for routine use
- Warnings / precautions: The product does not contain hazardous substances in concentrations exceeding the limits set by current legislation and therefore is notclassified as dangerous. it is nevertheless recommended to consult the safety data sheet for its correct us. The product is designed for professional use only and must be used by properly trained operators.
- Storage / shelf life: The powder is very hygroscopic: store the powder at 10-30°C, in a dry environment, in its original container tightly closed and use it before the expiry date on the label or until sings of deterioration or contamination are evident. WARNING AND
- Waste disposal: OF WASTEDisposal of waste must be carried out according to national and local regulations in force.REFERENCES1.ISO 29981/IDF 220: 2010. Milk products - Enumeration of presumptive bifidobacteria - Colony count
Safety and documentation points
- Hazards: 2.1 Classification of the substance or mixture Classification according to Regulation (EC) No 1272/2008 [EU-GHS/CLP] Acute Tox. 4, Acute toxicity in contact with skin (Category 4); H312 2.2 Label elements Labelling according Regulation (EC) No 1272/2008 [CLP] Pictogram Signal word Warning Hazard statement(s) H312 Harmful in contact with skin. Precautionary statement(s) P101 P102 P280 P302+P352 P312 P501 If medical advice is needed, have product container or label at hand.
- Exposure controls: 8.1 Control parameters Components with workplace control parameters Contains no substances with occupational exposure limit value. 8.2 Exposure controls Exposure controls Handle in accordance with good hygiene and safety practice. Wash hands before breaks and at the end of workday. Personal protective equipment Eyes/Face Protection: It is advisable wear safety goggles Skin protection: Handle with gloves Body Protection: Use protective clothes in accordance with laboratory good practices.
- Disposal: 13.1 Waste treatment methods Product Not be disposed of with household waste. Do not discharge into sewers. The product must be specially treated adhering to official regulations administrative. Offer surplus and non-recyclable solutions to a licensed
What to verify before ordering
- Kormay SKU: KB74610378
- Catalog/document code matched: 610378, 29981
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/tos-propionate-agar-base-for-microbiology-lab-testing