Molecular Weight: 66800

Storage: F, D

[C=Cold D=Desiccated F=Frozen L=Light Sensitive RT=Room Temperature]

CAS Number: [N/A]

Unit Price (USD): 2 mg $86.86

Bulk Price/unit (when you buy 5 or more): $69.49

Description:
Useful for detection of extracellular galactosidase activity, from enzyme-linked antibody systems or for endocytosis experiments, measurement of lacY permease activity, or microinjection analyses.

Application:
A conjugate of bovine serum albumin (BSA, MW = 66.4K) and the beta-galactosidase substrate carboxyumbelliferyl beta-D-galactopyranoside (Product M0257). The resulting coumarin-BSA conjugate has fluorescence excitation and emission spectra similar to 3-carboxyumbelliferone (Ex = 386nm; EM = 445nm, e=32K) (blue fluorescence). Note: The fluorescence spectrum for 3-carboxyumbelliferone is pH-dependent. Below the pKa (7.8), Abs shifts to shorter wavelengths (325–340 nm) and fluorescence intensity decreases. These shifts may be used to measure compartmentalization of intracellular activity. See the references below for applications of this substrate for the detection of galactosidase activity.

References:

• Armenta, R., Tarnowski, T., Gibbons, I., Ullman, E.F.,"Improved sensitivity in homogeneous enzyme immunoassays using a fluorogenic macromolecular substrate: an assay for serum ferritin." (1985) Anal. Biochem. 146:211-219
• Holst, B.D., Vanderklish, P.W., Krushel, L.A., Zhou, W., Langdon, R.B., McWhirter, J.R., Edelman, G.M., Crossin, K.L.,"Allosteric modulation of AMPA-type glutamate receptors increases activity of the promoter for the neural cell adhesion molecule, N-CAM." (1998) Proc. Natl. Acad. Sci. USA 95:2597-2602.
• Burd J.F.,"The homogeneous substrate-labeled fluorescent immunoassay." (1981) Methods Enzymol. 74(C):79-87.