ColiComplete Kit

AOAC Official Method 992.30

X-Gal, MUG

ColiComplete contains 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (X-Gal) and 4-methyl umbelliferyl-β-D-glucuronide (MUG). Discs are added to LST inoculated with selected dilutions of samples. Samples are incubated at 35 - 37 ^oC and examined after 24 and 48 ± 2 h for confirmed total coliforms and after 30 ± 2 h for confirmed E. coli results. β-Galactosidase, from coliforms present in samples, cleaves X-Gal into 5-bromo-4-chloro-indoxyl intermediate which undergoes oxidation to yield water-insoluble blue dimer, visually detectable on disc or in surrounding medium as confirmed positive result for total coliform activity. β-Glucuronidase, from E. coli present in samples, cleaves MUG into glucuronide and methyl umbelliferone, which fluoresces under long wave UV light (366 nm) as confirmed positive result for E. coli presence.
NOTE: As E. coli O157:H7 does not produce β-glucuronidase, ColiComplete is not suitable for the detection of E. coli O157:H7.

ColiComplete is a patented substrate supporting disc method containing both XGAL and MUG. It is designed to simultaneously detect Total Coliforms and E. coli in food products. The β-galactosidase enzyme produced by coliforms reacts with the chromogenic XGAL substrate to produce a visually detectable insoluble blue dye. The β-glucuronidase enzyme found in E. coli reacts with the MUG substrate to produce a blue fluorescent reaction under long wave UV light.

containing 5-bromo-4-chloro-3-indolyl-ß-D-galactopyranoside (X-Gal) and 4-methyl umbelliferyl-ß-D-glucuronide (MUG)

Bottle of reagent discs

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