MUG Disk

Cat. no. Z17 MUG Disks 25 disks/jar

INTENDED USE

Hardy Diagnostics MUG Disks are recommended for the identification of glucuronidase activity in E. coli by fluorescence, under a long-wave (365nm) UV light source.

SUMMARY

Hardy Diagnostics MUG Disks are used to aid in the detection of Escherichia coli from water and food samples by fluorogenic means. The enzyme ß-glucuronidase hydrolyzes MUG (4-methylumbelliferyl-ß-D-glucuronide) to 4-methylumbelliferone, which exhibits a bluish fluorescence under a 365nm, long-wave, UV light source. The association of ß-glucuronidase in E. coli has been described at 97%. (1) All other Escherichia species are phenotypically ß-glucuronidase negative, including E. coli 0157:H7.

reagent FORMULA

MUG Disks are prepared by impregnating MUG (4-methylumbelliferyl-ß-D-glucuronide) onto a high quality filter paper disk.

STORAGE AND SHELF LIFE

Storage: Upon receipt store frozen at less than -20ºC. away from direct light. Disks should not be used if there are any signs of deterioration or discoloration.

PRECAUTIONS

PROCEDURE

1. Place the MUG Disk in an empty petri dish.

2. Lightly moisten disk with distilled or deionized water. Do no saturate.

3. Using a sterile loop, pick 2 to 3 well isolated, 18-24 hour old colonies and rub into a small area of the MUG Disk so that there is a visible paste.

4. Incubate the disk for 30 minutes at 35ºC.

5. After incubation, examine the disk under a long-wave UV light (365nm) for fluorescence.

INTERPRETATION OF RESULTS

Fluorescence of a bluish color indicates a positive test. A negative test is indicated by the absence of fluorescence.

LIMITATIONS

E. coli 0157:H7 will be MUG negative.

MATERIALS REQUIRED BUT NOT PROVIDED

Standard microbiological supplies and equipment such as loops, swabs, applicator sticks, other culture media, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided. A long-wave, 365 nm, UV light source is not provided.

QUALITY CONTROL

Test Organisms Reaction
Escherichia coli
ATCC ® 25922
Positive; Fluorescence under long-wave UV light
Proteus mirabilis
ATCC ® 12453
Negative; No fluorescence under long-wave UV light

USER QUALITY CONTROL

Physical Appearance

MUG Disks should appear white in color.

REFERENCES

1. Kilian, M., & Bulow, P. 1976. Acta Pathol. Microbiol. Scand, Sect. B. 84, 245-251.

2. Koneman, E.W., et al. Color Atlas and Textbook of Diagnostic Microbiology, J.B. Lippincott Company, Philadelphia, PA.

3. American Public Health Association. Standard Methods for the Examination of Water and Wastewater, APHA, Washington, D.C.

4. Association of Official Analytical Chemists. Official Methods of Analysissm, AOAC, Washington, D.C.

5. American Public Health Association. Standard Methods for the Examination of Dairy Products, APHA, Washington, D.C.

6. APHA Technical Committee on Microbiological Methods for Foods. Compendium of Methods for the Microbiological Examination of Foods, APHA, Washington, D.C.

7. U.S. Food and Drug Administration. Bacteriological Analytical Manual. AOAC, Arlington, VA.
http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm2006949.htm.

ATCC is a registered trademark of the American Type Culture Collection.

032116gr