Letheen Broth, Modified

Cat. no. K293 Letheen Broth, Modified, 16x125mm Tube, 9ml 20 tubes/box
Cat. no. U268 Letheen Broth, Modified, 125ml polycarbonate Bottle, 45ml 16 bottles/box
Cat. no. U293 Letheen Broth, Modified, 8oz Wide Mouth Jar, 90ml 12 jars/box
Cat. no. U355 Letheen Broth, Modified with Tween® 80, 1.5%, 1L Polypropylene Bottle, 1000ml 10 bottles/box
Cat.no. X68 Letheen Broth, Modified with Tween® 80, 1.5%, 50ml Polypropylene Tube, 10ml 25 tubes/box

INTENDED USE

Hardy Diagnostics Letheen Broth, Modified is for use in microbial recovery from personal care products and for the neutralization of quaternary ammonium compounds in the testing of germicidal activity. (1,2)

This product is not intended to be used for the diagnosis of human disease.

SUMMARY

Quaternary ammonium compounds are molecules which contain a nitrogen atom bonded to four other atoms. Most quaternary ammonium compounds are organic compounds that have biological activity. These compounds often work well as disinfectants, offering bactericidal and bacteriostatic effects. Letheen Broth, Modified is used in the AOAC procedure for determining the effects of these bactericidal compounds. (1)

Letheen Broth, Modified is formulated as described in the U.S. FDA Bacteriological Analytical Manual and is recommended by the FDA for use in the microbiological examination of cosmetics; the FDA also mentions the use of this medium as a suitable enrichment broth for the identification of contaminants from non-sterile pharmaceutical products. (2,3) The medium contains beef extract and peptone which provide a nutrient rich source of vitamins, amino acids and nitrogen to support the growth of a variety of microorganisms. Yeast extract provides vitamins and co-factors which serve as additional sources of nitrogen and carbon required for bacterial growth. Letheen Broth, Modified also contains lecithin and Tween ® 80. Quaternary ammonium compounds are neutralized by lecithin while phenolic disinfectants and hexachlorophene are neutralized by Tween ® 80. Together, lecithin and Tween ® 80 neutralize ethanol. (1)

FORMULA

Ingredients per liter of deionized water:*

Letheen Broth 25.7gm
Proteose Peptone No. 3 10.0gm
Casein Peptone 5.0gm
Yeast Extract 2.0gm
Sodium Bisulfite 0.1gm

In addition, Letheen Broth, Modified with Tween® 80, 1.5% (Cat. nos. U355 and X68) contains:

Tween® 80 10.0gm

Final pH 7.2 +/- 0.2 at 25°C.

* Adjusted and/or supplemented as required to meet performance criteria.

STORAGE AND SHELF LIFE

Storage: Upon receipt store at 2-8°C away from direct light. Media should not be used if there are any signs of deterioration, discoloration, contamination, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.

PRECAUTIONS

PROCEDURE

Consult AOAC and the U.S. FDA Bacteriological Analytical Manual for appropriate methods using Letheen Broth, Modified. (1-3)

INTERPRETATION OF RESULTS

Growth is indicated by turbidity in the medium. Subculture to a solid medium is necessary for confirmation and further identification. See appropriate references for the interpretation of growth in Letheen Broth, Modified. (1,3,4)

LIMITATIONS

MATERIALS REQUIRED BUT NOT PROVIDED

Standard microbiological supplies and equipment such as loops, swabs, applicator sticks, other culture media, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided.

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Letheen Broth, Modified
Staphylococcus aureus
ATCC® 25923
J 24hr 30-35°C Aerobic Growth; turbidity
Escherichia coli
ATCC® 25922
J 24hr 30-35°C Aerobic Growth; turbidity
Letheen Broth, Modified with Tween® 80, 1.5% (Cat. nos. U355 and X68):**
Candida albicans
ATCC® 10231
J 1-3days 35°C Aerobic Growth; turbidity
Escherichia coli
ATCC® 25922
J 1-3days 35°C Aerobic Growth; turbidity
Staphylococcus aureus
ATCC® 25923
J 1-3days 35°C Aerobic Growth; turbidity

** Tested in accordance with USP.(4)

USER QUALITY CONTROL

Physical Appearance

Letheen Broth, Modified and Letheen Broth, Modified with Tween® 80, 1.5% should appear slightly opalescent, light to medium amber in color, and may have slight precipitate.

REFERENCES

1. Association of Official Analytical Chemists. Official Methods of Analysis , AOAC, Washington, D.C.

2. U.S. Food and Drug Administration. Bacteriological Analytical Manual. AOAC, Arlington, VA.
http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm2006949.htm.

3. U.S. Food and Drug Administration. Guide to Inspections of Microbiological Pharmaceutical Quality Control Laboratories . Silver Springs, MD. http://www.fda.gov/ICECI/Inspections/InspectionGuides/ucm074914.htm

4. United States Pharmacopoeia and National Formulary (USP-NF). Rockville, MD: United States Pharmacopeial Convention.


ATCC is a registered trademark of the American Type Culture Collection.
Tween is a registered trademark of ICI Americas, Inc.

102616hlh