Name: China Chemical Factory Supply High Quality 4-Methylumbelliferyl-beta-D-glucuronide CAS 6160-80-1
Brand: Wuhan Fortuna Chemical Co., Ltd.

Items	Specifications	Results
Appearance	Colorless crystals or white crystalline powder	White crystalline powder
Water content(Karl Fischer)	8.0%-10.2%	9.33%
Purity(HPLC)	≥99.0%	99.73%
Assay	-103.0°---- -107.0°	103.81°
Conclusion	The product conforms to the above specifications.

4-Methylumbelliferyl-β-D-glucuronide (MUG) is a synthetic, fluorogenic enzyme substrate. It consists of two parts:

4-Methylumbelliferone (4-MU): A fluorescent blue molecule.
β-D-Glucuronic Acid: A sugar acid.

These two parts are linked by a beta-glycosidic bond. The key property is that MUG itself is non-fluorescent. However, when the enzyme β-glucuronidase (GUS) cleaves this bond, it releases the highly fluorescent 4-methylumbelliferone. This reaction allows for extremely sensitive detection and quantification of the enzyme's activity.

2. Primary Uses in "Chemical Grade"

"Chemical grade" or "reagent grade" MUG is supplied with high purity and detailed specifications for scientific and diagnostic applications, not for therapeutic use. Its uses are almost exclusively in laboratories:

a. Microbiology & Water Safety Testing

Principle: The enzyme β-glucuronidase is a key marker for Escherichia coli (E. coli).
Application: MUG is incorporated into culture media (as in the Colilert® test). If E. coli is present, its GUS enzyme hydrolyzes MUG, producing a fluorescent glow under UV light. This provides a rapid, specific, and sensitive method for detecting fecal contamination in water, food, and environmental samples.

b. Molecular & Cell Biology (GUS Reporter Assay)

Principle: The gusA gene, which codes for β-glucuronidase, is a widely used reporter gene in genetic engineering.
Application: Researchers fuse the gusA gene to a promoter of interest (e.g., from a plant gene) and introduce it into cells (commonly plants). When the promoter is active, GUS is produced. Adding MUG to tissue extracts or incubating whole tissues with it allows visualization and quantification of gene expression through fluorescence. For histology, a similar substrate (X-Gluc) that yields a blue precipitate is often used.

c. Biochemical & Pharmacological Research

Principle: β-glucuronidase activity is involved in drug metabolism, bacterial pathogenesis, and lysosomal function.
Application: Chemical-grade MUG is used as a standardized substrate to:

Measure enzyme kinetics and inhibition.
Study lysosomal storage disorders.
Screen for inhibitors that could serve as new therapeutics.
Investigate the metabolism of drugs that form glucuronide conjugates.

d. Diagnostic Enzymology

Principle: Abnormal levels of β-glucuronidase can indicate certain diseases.
Application: MUG serves as the core substrate in clinical chemistry assays to measure GUS activity in human serum or tissues, which can be a biomarker for conditions like certain cancers or liver diseases.

Key Characteristics of Chemical Grade MUG

High Purity (e.g., ≥99% by HPLC): Essential for consistent, reproducible results and to avoid background fluorescence.
Defined Specifications: Includes data on extinction coefficient, fluorescence properties, and limits for impurities.
Packaging: Labeled "For research use only" or "For in vitro diagnostic use," stored to ensure stability (often desiccated, frozen, and protected from light).
Supplier: Sold by fine chemical and biochemical suppliers (e.g., Sigma-Aldrich, Thermo Fisher, Toronto Research Chemicals).

Summary

Chemical-grade 4-Methylumbelliferyl-β-D-glucuronide is a critical fluorogenic reagent. Its sole purpose is to act as a precise detection tool for the enzyme β-glucuronidase. This makes it indispensable in water microbiology for E. coli detection, molecular biology as a reporter assay, and biochemical research for studying enzyme function and disease mechanisms.