Fraser Broth Base (Powder)

Isolation of Listeria sp. from food and environmental materials. Description: Fraser Broth Base was first described by Fraser and Sperber and is used for the rapid detection of Listeria from food and environmental samples. Peptones and yeast extracts supply necessary growth nutrients. The phosphate salts supply buffering capacity. The addition of esculin and ferric ammonium citrate detect esculin hydrolyzing bacteria (Listeria). The broth is made selective by the addition of antibiotics and other agents. Lithium chloride inhibits Enterococcus sp. which also hydrolyze esculin. Nalidixic acid inhibits the growth of Gram negative microorganisms and acriflavine inhibits Gram positive microorganisms, Storage: Store the sealed bottle containing the dehydrated medium at 2 to 8.0°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. Appearance: Light beige, homogeneous, free flowing powder. Solubility: Yellow, hazy to clear, complete with upper 10% of solution light to medium red upon standing. pH (25°C): 7.2±0.2, Microbiological Analysis: Escherichia coli ATCC 25922: Inhibited, Listeria monocytogenes ATCC 7644: Growth, Staphylococcus aurous ATCC 25923: Inhibited , , Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.