Intended Use

For the determination of Escherichia coli in drinking water and its source water by multiple tube fermentation method.

Principle and Interpretation

MUG permits the rapid detection of Escherichia coli when the medium is observed for fluorescence using a UV light. MUG is hydrolyzed by the enzyme β-glucuronidase which is produced by E. coli to yield a fluorescent end product 4- methylumbelliferone. Trypticase provides the essential nutrients. Lactose is the fermentable carbohydrate. Sodium chloride maintains the osmotic equilibrium. The medium has a strong buffering system to control the pH in the presence of fermentative action. The bile salts inhibit gram-positive bacteria especially the Bacillus species and faecal Streptococci.

Formulation

Ingredients	/liter
Trypticase or tryptose	20 g
Bile salts No. 3	1.5 g
Lactose	5 g
K2HPO4	4 g
KH2PO4	1.5 g
NaCl	5 g
4-methylumbelliferyl-β-D-glucuronide (MUG)	50mg
pH6.9±0.2 at 25°C

Preparation

Weigh 37g of dry powder of this product, add 1L of distilled water or deionized water, stir, heat and boil until

completely dissolved,  sterilize at 115℃ for 20min, cool to room temperature and set aside.

Quality Control

The following quality control strains were inoculated and cultured at 44.5℃±0.5℃ for 24h. The results are as follows:

Quality control strains	Growth
Escherichia coli ATCC25922	Blue-white fluorescence is produced under 366nm UV light
Salmonella typhimurium ATCC14028	No fluorescence under 366nm UV light
Enterococcus faecalis ATCC29212	Clear, no fluorescence

Storage and Shelf Life

2-30℃，Keep container tightly closed, avoid direct sunlight.

Use before expiry date on the label.

 Precautions

1. When weighing the dehydrated medium, please wear masks to avoid causing respiratory system discomfort

2. Keep container tightly closed after using to prevent clumping.

Waste Disposal

Microbiological contamination was disposed by autoclaving at 121°C for 30 minutes.