1-Naphthyl ?-D-mannopyranoside is a fluorescent chemiluminescent substrate that can be used in the detection of alkaline phosphatase, esterase, and other enzymes. It is also an enzyme substrate in chemical assays for direct determination of glucose and fructose. 1-Naphthyl ?-D-mannopyranoside has been shown to be an effective bioluminescence substrate for the firefly luciferase system. This product has been tested for use in diagnostics and as a chromogenic substrate for staining.