4-Methylumbelliferyl alpha-D-glucopyranoside

4-Methylumbelliferyl-alpha-D-glucopyranoside is a non-fluorescent but sensitive fluorogenic substrate for alpha-glucosidase yielding a blue fluorescent solution. 4-Methylumbelliferyl-alpha-D-glucopyranoside is cleaved by alpha-glucosidase to release the fluorescent moiety 4-methylumbelliferyl (4-MU). 4-MU fluorescence is pH-dependent with excitation maxima of 320 and 360 nm at low (1.97-6.72) and high pH (7.12-10.3), respectively, and an emission maximum ranging from 445 to 455 nm, increasing as pH decreases. 4-Methylumbelliferyl-alpha-D-glucopyranoside has been used to quantify alpha-glucosidase activity in infant blood spot samples as a biomarker of Fabry and Pompe diseases, lysosomal storage disorders characterized by a deficiency in the enzyme and and fundamental research into carbohydrate-metabolizing enzyme function. Spectral Data: lambdaEx/lambdaEm= 360/450 nm (cleaved product, pH-dependent).