X-GAL, powder

X-Gal (5-Bromo-4-Chloro-3-Indolyl-ß-D-galactopyranoside) is a β-galactosidase substrate. In the presence of β-galactosidase, X-Gal is hydrolyzed and yields a blue precipitate.

Application Notes

X-Gal is used for the identification and selection of galactosidase producing bacteria (bacteria Lac+). X-Gal is particularly useful in molecular biology applications to detect the activity of β-galactosidase which is frequently used as a reporter gene. In cloning, X-Gal is used to detect insertion of foreign DNA into the lacZ region of plasmid DNA using α complementation which is based on vectors such as the pUC and the M13mp series that carry a fragment of the β-galactosidase gene encoding an α-fragment of β-galactosidase. Insertion of DNA into the lacZ region results in the loss of β-galactosidase activity. Lac? bacterial colonies resulting from α-complementation will appear blue whereas bacterial colonies containing plasmid with DNA inserted in the lacZ region, will be incapable of α-complementation and will appear white. Many other applications also use X-Gal as a substrate to detect β-galactosidase activity, which include β-galactosidase-antibody linked immunoassays and immunohistochemistry, coliphage detection based on β-galactosidase induction, and the detection of micrometastasis formation during tumor progession.

Usage Statement

Unless specified otherwise, MP Biomedical's products are for research or further manufacturing use only, not for direct human use. For more information, please contact our customer service department.

Key Applications

Cell culture |Proteomics |Purification and Detection |Protein Analysis |Yeast Culture |Plasmid Production |Protein Expression |Gene Expression |Cloning |Gene Function |Gene Regulation |Automated Bacterial Growth Media |S. cerevisiae Culture