X-GlcA Sodium Salt Trihydrate

X-GlcA Sodium Salt Trihydrate (5-Bromo-4-chloro-3-indolyl β-D-glucuronide sodium salt trihydrate, CAS 370100-64-4) is a chromogenic substrate essential for histochemical detection of β-glucuronidase (GUS, EC 3.2.1.31) activity in molecular biology, microbiology, and plant science research. Hydrolysis by β-glucuronidase cleaves the β-glycosidic bond, releasing 5-bromo-4-chloro-3-indoxyl, which spontaneously oxidizes and dimerizes to form an insoluble blue-black indigo precipitate, enabling precise spatial localization of enzyme activity in tissues, colonies, and cells without diffusion. The sodium salt trihydrate form offers superior water solubility (>10 mg/mL) compared to cyclohexylammonium salts, making it ideal for agarose overlays, whole-mount staining, and high-throughput screening of GUS reporter gene expression in transgenic plants (Arabidopsis, tobacco), bacterial transformation (E. coli), and mammalian glucuronidation studies with exceptional signal retention and minimal background.

Appearance

• White to off-white crystalline powder, mildly hygroscopic.
• Highly water-soluble forming clear colorless solutions (10-50 mM).

Source

• Glycosylation of 5-bromo-4-chloro-3-indolol with protected glucuronic acid donors (Koenigs-Knorr), followed by sodium salt formation and trihydrate crystallization.
• Commercial molecular biology grade from AG Scientific, Duchefa, Melford.

Molecular Weight and Structure

• C14H12BrClNNaO7·3H2O, 498.64 g/mol (anhydrous 444.59 g/mol).
• 5-Br-4-Cl-3-indolyl β-D-GlcA sodium salt; β-glycosidic linkage cleaved by GU

Sugar Specificity

• Highly specific for β-glucuronidases (EC 3.2.1.31); Km 50-200 μM.
• Negligible hydrolysis by β-glucosidases or β-galactosidases.

Biological Activity

• GUS hydrolysis → indolyl + glucuronic acid → blue-black precipitate (insoluble).
• Optimal pH 5.2-7.0, 37°C; visible color in 30 min-2h depending on enzyme level.

Purity and Microbial Contamination

• ≥98.5% HPLC purity; β-anomer >98%; endotoxin-free.
• Sterile lyophilized; no contaminating β-glucuronidase activity.

Identity and Quality Control

• LC-MS (m/z 445.0 [M+Na]+), 1H-NMR (β-anomer J1,2=7.9 Hz), functional GUS assay.
• TLC single spot; CAS verified; Ph. Eur. equivalent purity.

Shelf Life and Storage

• 3-5 years at -20°C desiccated; amber vials, avoid moisture/light.
• Aqueous stocks stable 6 months -20°C; working solutions same day.

Application

• GUS reporter gene detection in transgenic plants and bacteria.
• coli O157:H7 coliform detection; whole-mount embryo staining.
• Glucuronidase histochemistry; enzyme localization studies.

Key Characteristics

• Insoluble blue-black precipitate prevents diffusion; high spatial resolution.
• Water-soluble sodium salt; non-toxic; superior to X-GlcA cyclohexylamine salt.

Citation Links

• http://chemsynlab.com/en/product/370100-64-4.html
• https://agscientific.com/products/enzymes/enzymes-m-z/x-glca-sodium-salt-100-mg.html
• https://www.labproservices.com/buy-x-glca-sodium-salt-100-mg-cas-12954-41-9-b72100-0-1-ea.html
• https://filarabiomed.ro/en/product/x-glc-sodium-salt-trihydrate/
• https://hepattack.com/en/product03_cid_212_pid_486.html
• https://www.melford.co.uk/products/biochemicals/enzyme-substrates/x-glca-sodium-salt-25-g.html
• https://duchefa-biochemie.com/product/details/number/X1406
• https://www.melford.co.uk/products/biochemicals/enzyme-substrates/x-glca-sodium-salt-500-mg.html
• https://www.sigmaaldrich.com/IN/en/search/x-glca?focus=products&page=1&perpage=30&sort=relevance&term=x-glca&type=product
• https://discofinechem.com/products/5-bromo-4-chloro-3-indoyl-beta-d-glucuronide-sodium-salt/