Product Overview
Use: Letheen Agar Base is used to determine bactericidal activity of quaternary ammonium compounds.
Description: Letheen Media is highly nutritional media containing Lecithin and Tween 80 which are used for neutralizing quaternary ammonium compounds. These media are modifications of an AOAC formula. Letheen Broth Base is used for determining the phenol coefficient of quaternary compounds.
Formula* per Liter:
- Peptic Digest of Animal Tissue..... 10.0g
- Beef Extract ...................................... 5.0g
- Sodium Chloride .............................. 5.0g
- Lecithin .............................................. 0.7g
Final pH: 7.0 ± 0.2 at 25.0°C
* Grams per liter may be adj. or formula supplemented to obtain desired performance
Preparation: Mix 20.7 grams of the medium and 5 grams of Tween 80 in one Liter of purified water until evenly dispersed. Heat with repeated stirring and boil for one minute to dissolve completely. Distribute and autoclave at 121.0°C for 15 minutes.
Quality Control Specifications:
- The powder is homogeneous, free flowing and light beige.
- Visually the prepared agar is light to medium amber and clear.
- Expected cultural response after 18-24 hours at 35.0°C.
Organism                                                                               Result
Escherichia coli ATCC 25922Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Growth
Staphylococcus aureus ATCC 25923Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Growth
Storage: Store the sealed bottle containing the dehydrated medium at 2 to 30.0°C. Once opened and recapped, place the container in a low humidity environment at the same storage temperature. Protect it from moisture and light. The dehydrated medium should be discarded if it is not free flowing or if the color has changed from the original light beige color.