Supplements and additives
Potassium Tellurite 1%
Aqueous solution of potassium tellurite at 1%, sterilized by filtration and suitable for use as an inhibitor additive in culture media.
- Cat. No.
- LC-5209
- Category
- Supplements and additives
- Format
- 100 mL flask
- Storage
- 15 to 25 °C
- Minimum guaranteed shelf life
- 10 months
Potassium Tellurite Solution is added to culture media as an inhibitor. Its purpose is to prevent the growth of most Gram-negative bacteria and of those Gram-positive bacteria unable to reduce it.
Key features
Applications
Selective isolation of corynebacteria, Staphylococcus and Streptococcus.
Industry
Clinical, food.
Presentation
1 bottle, 125 mL, with 100 ± 3 mL.
Packaging
1 box with 1 bottle (amber) 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
It is used in media such as Giolitti-Cantoni Broth, Vogel-Johnson Agar, Baird Parker and other selective media for staphylococci. This solution is also contained in selective media for corynebacteria, streptococci and vibrios.
There is a high correlation between the ability to reduce potassium tellurite to tellurium and the pathogenicity of staphylococci; therefore, the presence of potassium tellurite in a medium, together with other tests, helps to determine staphylococci of clinical interest. Potassium Tellurite Solution should be stored at room temperature, since low temperatures will cause crystallization and later precipitation of the product. Should this occur, intense agitation will help redissolve the sediment. Due to its thermolability, it is recommended not to subject potassium tellurite to temperatures above 40 °C.
Note: this product is transparent, but precipitates may appear without affecting the performance of the medium.
Presentation
| Presentation | 1 bottle, 125 mL |
|---|---|
| Filling | 100 ± 3 mL |
| Packaging | 1 box with 1 bottle (amber) 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 |
|---|---|
| Potassium tellurite | 10.0 |
| Sterile water | 1000 mL |
Reagent to be added, as an inhibitor, into culture media for staphylococci isolation.
Quality control
Physical/chemical control
| Color | Transparent/colourless |
|---|
Microbiological control
Add the supplement into Giolitti-Cantoni Broth Base medium, for functionality testing.
Inoculate: practical range 100 ± 20 CFU, min. 50 CFU (productivity) / 10⁴-10⁶ (selectivity).
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 |
|---|---|
| Stph. aureusATCC 25923, WDCM 00034 | Good - black precipitate |
| Staphylococcus aureusATCC 6538, WDCM 00032 | Good - black precipitate |
| Escherichia coliATCC 8739, WDCM 00012 | Inhibited |
Sterility control
Incubation 48 hours at 30-35 °C and 48 hours 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. London.
- BAIRD-PARKER, A.C. (1962) An improved diagnostic and selective medium for isolating coagulase-positive staphylococci. J. Appl. Bact. 25:12.
- COLIPA (1997) Guidelines on Microbial Quality Management (MQM). Brussels.
- DOWNES, F.P. & K. ITO (2001) Compendium of Methods for the Microbiological Examination of Foods. 4th ed. APHA. Washington. USA.
- EUROPEAN PHARMACOPOEIA (2007) 5th ed. Suppl. 5.6 § 2.6.13 Microbiological examination of non-sterile products. EDQM. Council of Europe. Strasbourg.
- FIL-IDF 60:2001 Standard. Lait et produits à base de lait - Detection des staphylocoques à coagulase positive - Technique du nombre le plus probable. Brussels.
- ISO 5944:2001 Standard. Milk and Milk based products - Detection of coagulase positive staphylococci - MPN Technique. Geneva.
- ISO 6888-1:1999 Standard. Microbiology of food and animal feeding stuffs - Horizontal method for the enumeration of coagulase-positive staphylococci - Part 1 Technique using Baird-Parker Agar medium. Geneva.
- ISO 11133:2014/Amd 1:2018. Microbiology of food, animal feed and water. Preparation, production, storage and performance testing of culture media.
- ISO 22718 Standard (2015). Cosmetics - Microbiology - Detection of Staphylococcus aureus.
- USP 31 - NF 26 (2008) <61> Microbial Limit Tests. US Pharmacopoeial Conv. Inc. Rockville. MD. USA.
- ZANGERL, P. & H. ASPERGER (2003) Media used in the detection and enumeration of Staphylococcus aureus. In Handbook.
What you receive
The product
Shipped under controlled temperature when the product requires it.
Lot certificate
Every lot comes with its certificate.
Tracked shipment
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