COLICOMPLETE

Application

AOAC Official Method 992.30

Components

Bottle of reagent discs

Features and Benefits

ColiComplete provides confirmed quantitative E. coli results in as few as 28 hours and confirmed total Coliforms result in 48 hours. Just add the patented ColiComplete disc to Lauryl Sulfate Broth (LST) tubes at the time of inoculation, incubate and read results. Use the Most Probably Number (MPN) format for quantitative results. No transfers are necessary. Simultaneous detection of both E. coli and total Coliforms from a single test. Results are confirmed and require no subculturing.

General description

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.

Legal Information

AOAC is a registered trademark of AOAC International

Principle

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.

Testing Method

X-Gal, MUG