Ready-to-use media
Letheen Broth
Liquid culture medium used for the determination of germicidal activity coefficients of cationic detergents.
- Cat. No.
- LC-5246
- Category
- Ready-to-use media
- Format
- 10 x 100 mL flasks
- Storage
- 8 to 25 °C
- Minimum guaranteed shelf life
- 4 months
Ready-to-use media in plates, contact plates, tubes, flasks and bags.
Key features
Applications
Enrichment with neutralizers.
Industry
Cosmetics.
Presentation
10 prepared bottles, 125 mL, with 100 ± 3 mL.
Packaging
1 box with 10 bottles 125 mL. Injectable cap: plastic screw inner cap. The use of syringe needles with a diameter greater than 0.8 mm is not recommended.
Description and technique
Collect, dilute and prepare samples and volumes as required according to specifications, directives, official standard regulations and/or expected results. Dispense liquid medium in appropriate containers if the original container is of large volume.
Inoculate aseptically the tubes with the prepared sample or its dilution.
Incubate the tubes tightly closed aerobically at 37 ± 1 °C for 24-48 h.
(Incubation times, temperature and sample volumes may vary depending on the sample, on the specifications, etc.)
Read the turbidity increase as growth indicator.
This medium can be used to inoculate any confirmatory, secondary medium by streaking methodology or by spiral method; after proper incubation, enumerate all the colonies that have appeared onto the surface of the secondary agar.
Each laboratory must evaluate the results according to their specifications.
Calculate total microbial count per mL of sample by multiplying the average number of colonies per plate by the inverse dilution factor if a diluted sample was streaked. Report results as colony forming units (CFU) per mL or g along with enrichment and secondary media used, incubation time and temperature.
Presentation
| Presentation | 10 prepared bottles, 125 mL |
|---|---|
| Filling | 100 ± 3 mL |
| Packaging | 1 box with 10 bottles 125 mL. Injectable cap: plastic screw inner cap. The use of syringe needles with a diameter greater than 0.8 mm is not recommended. |
Composition
| Ingredient | g/L |
|---|---|
| Meat peptone | 10.00 |
| Meat extract | 5.00 |
| Sodium chloride | 5.00 |
| Lecithin | 0.70 |
| Polysorbate 80 | 5.00 |
Quality control
Physical/chemical control
| Color | Yellowish-brown |
|---|---|
| pH | 7.0 ± 0.2 at 25 °C |
Microbiological control
Prepare tubes - inoculate: practical range 100 ± 20 CFU; min. 50 CFU (productivity).
Analytical methodology according to ISO 11133:2014/Amd 1:2018; A2:2020.
Aerobiosis. Incubation at 37 ± 1 °C, reading after 24-48 ± 2 h.
| Microorganism | Growth |
|---|---|
| Escherichia coliATCC 25922, WDCM 00013 | Good |
| Enterococcus faecalisATCC 19433, WDCM 00009 | Good |
| Ps. aeruginosaATCC 9027, WDCM 00026 | Good |
| Staphylococcus aureusATCC 6538, WDCM 00032 | Good |
| Bacillus subtilisATCC 6633, WDCM 00003 | Good |
| Candida albicansATCC 10231, WDCM 00054 | Good |
Sterility control
Incubation 48 h at 30-35 °C and 48 h at 20-25 °C: NO GROWTH.
Check at 7 days after incubation in same conditions.
Bibliography
- ATLAS, R.M., L.C. PARKS (1993) Handbook of Microbiological Media. CRC Press, Inc. London.
- HORWITZ, W. (2000) Official Methods of Analysis. AOAC International. Gaithersburg. MD. USA.
- ISO 11133:2014/Amd 1:2018. Microbiology of food, animal feed and water. Preparation, production, storage and performance testing of culture media.
- LUCAS, I.P. (1977) Microbiological Examination of Cosmetics. Newburger's Manual of Cosmetic Analysis AOAC. Washington.
- WEBER, G.R. & L.A. BLACK (1948) Relative efficiency of quaternary inhibitors. Soap and Sanit. Chem. 24:134-139.
What you receive
The product
Shipped under controlled temperature when the product requires it.
Lot certificate
Every lot comes with its certificate.
Tracked shipment
Follow your shipment live, from our warehouse to your lab.
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Frequently asked questions
Can I ask for formats other than those listed?
Yes: custom formats and OEM packs are available on request. Tell us the quantities you need.
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