4-Methylumbelliferyl α-D-glucopyranoside is used as a flurogenic substrate for the identification, characterization and kinetic analysis of α-D-glucosidases. 4-Methylumbelliferyl α-D-glucopyranoside is used for the high throughput screening of α-D-glucosidase inhibitors. It is also suitable for the diagnosis of Pompe′s disease (also known as acid-maltase disease and glycogen storage disease II) in kidney and leucocytes. Pompe disease is a rare genetic disorder that causes progressive weakness to the heart and skeletal muscles.