Carboxyumbelliferyl β-D-galactopyranoside (CUG)

Product ID: M0257

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Blue fluorogenic β-galactosidase substrate that is well retained intracellularly for use in live cell analyses.

The blue fluorogenic β-galactosidase substrate is well retained intracellularly for use in live cell analyses such as flow cytometry. It is provided as a High Purity-Molecular Biology Grade. The fluorescence spectrum for the released 3-carboxyumbelliferone is pH-dependent. Below the pKa (7.8), Abs. shifts to shorter wavelengths (325 to 340 nm) and fluorescence intensity decreases. These shifts may be used to measure compartmentalization of intracellular activity.

Technical Data
SKU M0257
CAS Number 64664-99-9
Unit Size 5mg
Absorption 330nm
Emission Wavelength 396
Extinction 16
Detection Method Fluorescence
Molecular Formula C₁₆H₁₆O₁₀
Molecular Weight 368.29
Storage Conditions -20C, Desiccated
Notes Em = 445nm, ε = 32K is emission of fluorophore 3-carboxyumbelliferone released upon beta-galactosidase enzyme activity.

References and Citations


  • Briciu-Burghina C, Heery B, Regan F. (2015) "Continuous fluorometric method for measuring β-glucuronidase activity: comparative analysis of three fluorogenic substrates." Analyst. 140(17):5953-64.
  • Jan TA, Chai R, Sayyid ZN, van Amerongen R, Xia A, Wang T, Sinkkonen ST, Zeng YA, Levin JR, Heller S, Nusse R, Cheng AG. (2013) "Tympanic border cells are Wnt-responsive and can act as progenitors for postnatal mouse cochlear cells." Development 140: 1196-1206.
  • Rodrigue J, Ganne G, Blanchard B, Saucier C, Giguère D, Shiao TC, Varrot A, Imberty A, Roy R. (2013) "Aromatic thioglycoside inhibitors against the virulence factor LecA from Pseudomonas aeruginosa." Org Biomol Chem. 11(40):6906-18.
  • Akselband Y, Cabral C, Castor TP, Chikarmane HM, McGrath P. (2006) "Enrichment of slow-growing marine microorganisms from mixed cultures using gel microdrop (GMD) growth assay and fluorescence-activated cell sorting."J. Exp. Mar. Biol. Ecol. 329: 196–205.
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  • Nazarenko DA, Dertinger SD, Gasiewicz TA.(2001) "Enhanced detection of b-galactosidase reporter activation is achieved by a reduction of hemoglobin content in tissue lysates." BioTechniques 30(4): 776-777, 780-781.

  • Huff JB, Merchant BT, Mullen CR, Venkata SRT. (1999) "Water soluble coumarin derivatives for use as fluorogenic enzyme substrates." PCT Int. Appl. WO 9946402.

  • Fierer J, Eckmann L, Fang F, Pfeifer C, Finlay BB, Guiney D. (1993) "Expression of the Salmonella virulence plasmid gene spvB in cultured macrophages and nonphagocytic cells." Infect Immun 61: 5231-5236.

  • Armenta R, Gibbons I, Olson J. (1987) "Reducing background interference activity in enzyme-label immunoassays." U.S. Patent US 4668620.

  • Johnson PK, Messenger LJ. (1986) "Homogeneous substrate-labeled fluorescent immunoassay for disopyramide in human serum: semi- and fully automated procedures." Clin Chem 32: 378-381.

  • Armenta R, Tarnowski T, Gibbons I, Ullman EF. (1985) "Improved sensitivity in homogeneous enzyme immunoassays using a fluorogenic macromolecular substrate: an assay for serum ferritin." Anal Biochem 146: 211-219.

  • Li TM, Miller JE, Ward FE, Burd JF. (1982)"Homogeneous substrate-labeled fluorescent immunoassay for carbamazepine." Epilepsia 23: 391-398.

  • Li TM, Benovic JL, Burd JF. (1981) "Serum theophylline determination by fluorescence polarization immunoassay utilizing an umbelliferone derivative as a fluorescent label." Anal Biochem 118: 102-107.

  • Li TM, Benovic JL, Buckler RT, Burd JF. (1981) "Homogeneous substrate-labeled fluorescent immunoassay for theophylline in serum." Clin Chem 27: 22-26.

  • Burd JF. (1981) "The homogeneous substrate-labeled fluorescent immunoassay." Methods Enzymol 74: Pt C, 79-87.

  • Boguslaski RC, Burd JF, Denning CE. (1980) "Substrate-labeled homogeneous fluorescent immunoassay for tobramycin, ASEAN." J. Clin. Sci. 1(3): 215-19 .

  • Krausz LM, Hitz JB, Buckler RT, Burd JF. (1980) "Substrate-labeled fluorescent immunoassay for phenobarbital." Ther. Drug Monit. 2(3): 261-72.

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