X-GAL

X1009969-1

5-Bromo-4-chloro-3-indolyl β⁠-D-galactopyranoside is most commonly known as X-Gal . X-gal is a histochemical substrate for β⁠-galactosidase which cleaves X-Gal to yield an insoluble blue precipitate. X-Gal is a mainstay in molecular biology cloning applications in which it is used to detect the activity of β⁠-galactosidase. X-Gal is used to detect the insertion of foreign DNA into the lacZ region of a plasmid DNA. Insertion of DNA into the lacZ region results in the loss of β⁠-galactosidase activity. X-gal is used to indicate whether a cell expresses the β⁠-glactosidase enzyme, which is encoded by the lacZ gene, in a technique called blue white screening. Bacterial cells that retain active β⁠-galactosidase will result in characteristic blue colonies. Successful disruption of the lacZα gene disrupts the α -complementation of the β⁠-galactosidase gene and the precipitate does not form, resulting in white colonies.

236-238 °C

698.00 °C at 760 mmHg