4-Nitrophenyl-beta-L-fucopyranoside is a high-quality pNP enzyme substrate developed for the sensitive detection and quantification of Beta-L-fucosidase activity. The enzymatic hydrolysis of the substrate generates 4-nitrophenol, a yellow chromogenic component that can be conveniently measured spectrophotometrically, allowing for accurate determination of enzyme concentration and kinetics. This substrate finds applications in various research fields, diagnostics, and industrial enzyme production.