X-GlcA Sodium Salt Anhydrous

X-GlcA Sodium Salt Anhydrous (5-Bromo-4-chloro-3-indolyl-β-D-glucuronide sodium salt, CAS 129541-41-9) is a chromogenic substrate essential for β-glucuronidase (GUS, EC 3.2.1.31) detection in molecular biology and microbiology, hydrolyzing to produce an insoluble intense blue precipitate (dibromo-dichloro-indigo) that enables clear visualization of GUS-positive colonies, plaques, or tissues. With formula C14H12BrClNNaO7 (MW 444.59 g/mol), this white powder features a β-D-glucuronopyranosyluronic acid moiety O-linked to 5-bromo-4-chloroindol-3-ol, remaining colorless until cleaved by bacterial (E. coli gusA), plant (uidA reporter), or mammalian β-glucuronidases, liberating the indoxyl that spontaneously dimerizes/oxidizes to the highly colored, localized indigo dye without requiring washes or equipment. The sodium salt enhances water solubility (>5 mg/mL) for uniform media incorporation (50-100 μg/mL), supporting GUS reporter gene systems in Agrobacterium-mediated plant transformation, lacZ/GUS fusion constructs, and E. coli O157:H7 detection in food/water safety testing. Superior to fluorogenic MUG for permanent archival staining and eye-readable results, it distinguishes recombinants (white, GUS-) from transformants (blue, GUS+) with >98% accuracy in IPTG-independent systems, while resisting spontaneous hydrolysis and interferents through haloaromatic stabilization.

Appearance

• White to almost white crystalline powder.
• Hydrolysis yields insoluble blue-black precipitate.

Source

• Koenigs-Knorr synthesis: protected β-D-glucuronosyl halide + bromochloroindol-3-ol, sodium salt formation.
• Commercial: Sigma-Aldrich, TCI (>98% HPLC), Duchefa.

Molecular Weight and Structure

• Formula: C14H12BrClNNaO7; MW 444.59 g/mol.
• Sodium (2R,3S,4S,5S,6S)-6-[(5-bromo-4-chloro-1H-indol-3-yl)oxy]-3,4,5-trihydroxyoxane-2-carboxylate.​

Sugar Specificity

• Selective β-D-glucuronopyranoside for β-glucuronidases (GUS).
• Negligible cross-reactivity with glucosidases/galactosidases.​

Biological Activity

• Chromogenic GUS reporter; non-toxic at working concentrations.
• 1000-fold color amplification localized to enzyme.​

Purity and Microbial Contamination

• 98% (HPLC/TLC); molecular biology grade.
• Synthetic; non-sterile reagent.​

Identity and Quality Control

• ¹H-NMR confirmed; solubility DMF/water (1:1).
• Characteristic blue product post-hydrolysis.

Shelf Life and Storage

• 2 years at 2-8°C; long-term -20°C desiccated.
• Protect from light/humidity.​

Applications

• GUS reporter assays (plant transformation, E. coli detection).
• Recombinant screening, food safety testing.​

Key Characteristics

• Water-soluble sodium salt; eye-readable blue colonies.
• Archival stable; orthogonal to X-Gal/lacZ.​

Citation Links

• https://pubchem.ncbi.nlm.nih.gov/compound/X-GlcA-Sodium-Salt​
• https://www.rpicorp.com/products/biochemicals/other-enzymes/x-glca-sodium-salt-1-g.html​
• https://pubchem.ncbi.nlm.nih.gov/compound/X-GlcA​
• http://www.cyrusbio.com.tw/upload/Brochure/pdf/Spec_X-GlcA.pdf​
• https://www.sigmaaldrich.com/US/en/product/sigma/b6650​
• https://www.tcichemicals.com/OP/en/p/B3621​
• https://biotech.labover.fr/download_public/X1405.0100-3.pdf​
• http://chemsynlab.com/cn/product/129541-41-9.html​
• https://duchefa-biochemie.com/msds/download/number/X1406/id/1847​
• https://www.duchefa-biochemie.com/msds/download/number/X1405/id/1837