Isopropyl Î²-D-1-thiogalactopyranoside, abbreviated IPTG, is a molecular biology reagent. This compound is used as a molecular mimic of allolactose, a lactose metabolite that triggers transcription of the lac operon.
- X-gal is an analog of lactose, and therefore may be hydrolyzed by the Î²-galactosidase enzyme which cleaves the Î²-glycosidic bond in D-lactose.
- X-gal (also abbreviated BCIG for 5-bromo-4-chloro-indolyl-Î²-D-galactopyranoside) is an organic compound consisting of galactose linked to a substituted indole. The compound was synthesized by Jerome Horwitz and collaborators in Detroit, MI, in 1964. The formal chemical name is often shortened to less accurate but also less cumbersome phrases such as bromochloroindoxyl galactoside.