
Biotech Grade X-Gal, (5-bromo-4-chloro-3-indolyl-beta-D-galacto-pyranoside) is a non-toxic, ready-to-use, stable formulation. The X-Gal is an inert chromogenic substrate for beta-galactosidase, which converts into 4-chloro-3-brom-indigo, which forms an intense blue precipitate. Induction of the lacZ gene with IPTG leads to the hydrolysis of X-Gal and to the development of blue colonies.