3-Indolyl-b-D-cellobioside is a fluorogenic substrate for alkaline phosphatase. It can be used in food testing, environmental testing, and diagnostics. 3-Indolyl-b-D-cellobioside is a chromogenic substrate for beta-galactosidase. It can be used in staining and enzyme substrates. 3-Indolyl-b-D-cellobioside is also a ligand for alkaline phosphatase. It can be used in conjugates and chemiluminescence or bioluminescence reactions.