4-Nitrophenyl 2-acetamido-3-O-acetyl-4,6-O-benzylidene-2-deoxy-aDglucopyranoside is a fluorogenic substrate that can be used for the detection of ?-glucosidase activity. It is a water soluble substrate with an extinction coefficient of approximately 10,000 M?1 cm?1 at 420 nm. 4NPAABGDG is a chromogenic substrate that can be used to detect ?-galactosidase activity. It has an extinction coefficient of approximately 1,700 M?1 cm?1 at 420 nm. The CAS number for 4NPAABGDG is 23262?56?8 and it is sold by Sigma Aldrich under catalog number L4959.