LACTOSE BROTH
Product Number L 5285
3. Members of the coliform group are defined as
Product Description aerobic and facultative anaerobic gram-negative,
Lactose Broth is used for the detection of coliform non-sporing bacilli; which ferment lactose with gas
bacteria in water, foods and dairy products. Lactose formation. In testing dairy products, Lactose Broth
Broth is recommended by the American Public Health is only used in the completed test (3). Large water
Association (APHA), for the presumptive test of coliform samples may require double-strength Lactose
bacteria in water, food and milk. The peptic digest of Broth to minimize the final volume.
animal tissue and beef extract supply the essential
nutrients to the organisms. Lactose is a fermentable Product Profile
carbohydrate for the coliforms. Appearance Yellow colored, homogeneous,
free flowing powder.
Components
Item g/L Color and Clarity Light to medium amber colored,
Peptic Digest of Animal Tissue 5.00 clear solution without any
Beef Extract 3.00 precipitate.
Lactose 5.00
Cultural Response Cultural characteristics are
observed after 18-48 hours at
Final pH (at 25 °C) 6.9 ± 0.2 35 °C.
Precautions and Disclaimer
For laboratory use only. Not for drug, household or Organisms (ATCC) GROWTH GAS
other uses. Enterobacter aerogenes (13048) luxuriant +
Escherichia coli (25922) luxuriant +
Preparation Instructions Pseudomonas aeruginosa luxuriant -
Suspend 13 grams of Lactose Broth in 1000 mls of (10145)
distilled water. Heat if necessary to dissolve the Enterococcus faecalis (29212) luxuriant -
medium completely. For larger inocula (10 ml or more) ,
concentrated medium may be prepared to account for
medium dilution by the inoculum, Dispense in tubes References
containing inverted Durham's tubes as desired. Sterilize 1. Standard Methods for the Examination of Water
by autoclaving at 15 lbs. pressure (121 °C) for and Wastewater, (1985). Greenberg, A., et al.,
15 minutes. eds. 16th Edition. APHA. Washington, D.C.
2. Compendium of Methods for the Microbiological
Storage Examination of Foods, (1984). Speck, M., ed. 2nd
Store the dehydrated medium at 24 °C and the Edition. APHA. Washington, D.C.
prepared medium at 2-8 °C. 3. Standard Methods for the Examination of Dairy
Products 15th ed. (1985), Richardson (Ed.),
Procedure A.P.H.A., Washington, D.C.
1. Tubes of Lactose Broth are inoculated with dilutions 4. American Type Culture Collection, Manassas, Va.,
of water or milk. U.S.A.
2. Incubate for 24-48 hours at 35 °C.
L5285 7/99
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Sigma-Aldrich, Inc. warrants that its products conform to the information contained in this and other Sigma-Aldrich publications. Purchaser
must determine the suitability of the product(s) for their particular use. Additional terms and conditions may apply. Please see reverse side of
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