Product overview
Liofilchem PA (Presence/Absence) Broth Culture Media 610317 is a Liofilchem microbiology product supplied by Kormay Biomedicals. Its practical role is pA (Presence-Absence) Broth is a selective medium for the detection of coliform bacteria in water. It is prepared according to the recommendations of standard methods (US-EPA) for the examination of water.
This product is relevant to water and beverage laboratories where filtration, enrichment, colony recovery, and indicator-organism interpretation are tied to release or investigation decisions.
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Where this product fits
Use this product where indicator organisms are part of a release, trend, or sanitation decision. The practical value comes from separating countable or presumptive target reactions from background flora so the analyst can document whether the sample meets the site limit.
Result signals and confirmation
Lactose-positive organisms form acid due to the fermentation of the lactose which colors the broth yellow. Gas formation can occur. To identify gas formation, the bottles are shaken gently and inspected to see if a foaming reaction occurs. All samples with acid and/or acid and gas formation are presumptive-positive and are inoculated for confirmation in Brilliant Green Bile Broth 2% (code 610010). If gas formation occurs during the incubation of 48 +/-3 hours at 35 +/- 0.5 °C, this can be seen as confirmation of the presence of coliforms in the 100 mL water sample.
Method principle
Peptones and meat extract give the nutrients and trace elements required for growth whereas the phosphate buffer and sodium chloride provide a good buffering capacity and the osmotic equilibrium. Lactose-fermenting organisms form acid which is identified by the pH indicator bromocresol purple as a color change from purple to yellow. The selective component of the culture medium is sodium lauryl sulphate which largely inhibits the undesired accompanying flora-with the exception of the coliforms.
Bench workflow
- Preparation: 1. Dissolve completely 91.5 g in 1 liter of distilled water, for the
- Procedure: 1. Collect water samples as described in recommended procedures(1,10) 2. Add 100mL water samples to the milk dilution bottles filled with 50 mL of triple strength concentrated broth. 3. Mix well. 4. Incubate at 35 +/- 0.5°C for up to 48 hours with a loose screw-cap in aerobic condition. 5. Read results after 24 hours and 48 hours.
Controls and performance checks
- Formula / composition: (g/L) Meat extract...................................................................... 3.0 Peptone............................................................................ 5.0 Lactose............................................................................. 7.46 Tryptose...………………………………………………....... 9.83 Dipotassium Hydrogen Phosphate.................................. 1.35 Potassium dihydrogen phosphate.................................... 1.35 Sodium chloride................................................................
Storage, limits, and safety
- Warnings / precautions: The product is not classified as hazardous by current legislation and does not contain harmful substances in concentrations of ≥1%. The product must be used only 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 signs of deterioration or contamination are evident. Store prepared media at 2-8°C. WARNING 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.
- 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.
- 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 o fficial regulations administrative. Offer surplus a nd non-recyclable solutions to a licensed
Ordering and documentation checks
- Kormay SKU: KB74610317
- Catalog/document code matched: 610317
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/pa-presence-absence-broth-for-microbiology-lab-testing