Home


 

Letheen Broth with Tween, Modified

Letheen Broth with Tween, Modified is used for the recovery of microorganisms from cosmetics in a laboratory setting. Letheen Broth with Tween, Modified is not intended for use in the diagnosis of disease or other conditions in humans.

In 1948, Weber and Black described the value of a highly nutritional solid medium containing neutralizing agents for quaternary ammonium compounds in sanitizers. The addition of Lecithin and Polysorbate 80 to Tryptone Glucose Extract (TGE) Agar resulted in a medium that effectively neutralizes quaternary ammonium compounds in testing of germicidal activity. Total neutralization of disinfectants is critical. Disinfectant residues can result in a false negative (no-growth) test.

Letheen Broth with Tween, Modified is based on the formula described in FDA Bacteriological Analytical Manual, and a modification of Letheen Broth Base. Letheen Broth with Tween, Modified is recommended by the FDA for use in the microbiological testing of cosmetics. Letheen Broth with Tween, Modified has incorporated Polysorbate 80 (Tween) into the medium.

 

Formula Liter
Letheen Broth Base 20.7 g
Enzymatic Digest of Casein 5 g
Enzymatic Digest of Animal Tissue 10 g
Yeast Extract 2 g
Sodium Bisulfite 0.1 g
Polysorbate 80 5 g

Final pH: 7.2 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.

Directions

  1. Dissolve 42.8 g of the medium in one liter of purified water.
  2. Heat with frequent agitation to completely dissolve the medium.
  3. Autoclave at 121°C for 15 minutes.

Order Details

Product # Product Description
7712A Letheen Broth with Tween, Modified, 500 g
7712T Letheen Broth with Tween, Modified, 5 kg