4-Methylumbelliferyl-β-D-xylopyranoside (MuX) can be used as substrate for the research of β-Xylosidase activity. 4-Methylumbelliferyl-β-D-xylopyranoside shows burst, steady-state kinetics, which supports the conclusion that hydrolysis of the glycosidic bonds for the substrate 4-Methylumbelliferyl-β-D-xylopyranoside is rapid[1][2].