EC Medium w/MUG (Powder)
USBio recommends that EC Medium be used for the determination of water pollution. The addition of 4-methylumbelliferyl-B-D-glucuronide (MUG) to EC Medium allows for the rapid detection (4-24 hours) of E coli when the incubated medium is observed for fluorescence using a long-wave UV light (365nm) source. It can also detect anaerogenic E. coli strains. Most strains of E. coli produce B-glucuronidase which hydrolyzes MUG to the fluorogenic compound 4-methyl-umbelliferone. Studies by Feng and Hartman noted that most E. coli strains (96%) and all enterotoxigenic E. coli strains (100%) and a moderate number of Salmonella (17%) and Shigella (40%) stains produce B-glucuronidase. False positives can also be caused by Streptococcus sp. To eliminate false positive results with oyster samples an enrichment step in Lauryl Sulfate Broth is recommended and then subsequent transfer to EC Medium with MUG.
Directions per Liter:
Dissolve 37g in 800-900ml of ddH2O stirring gently with heating until completely solubilized. Adjust pH of the medium to the desired level. Add additional water to bring the solution to1L. Dispense into appropriate containers, loosen caps and autoclave for 15 minutes at 121ºC (15psi).
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Storage and Stability:
Store powdered media at 4°C. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4°C and used within a short period of time.