The E. coli lacZ gene is among the most widely used marker genes for mammalian, yeast and bacterial transfection studies due in part to its resistance to intracellular proteolytic degradation. The lacZ gene encodes for the β-Galactosidase (β-Gal) enzyme that catalyzes the hydrolysis of a wide range of β-galactosides. When β-Gal cleaves the glycosidic linkage in X-Gal, a soluble, colorless indoxyl derivative is produced which quickly dimerizes and becomes oxidized to produce a bright blue indigo dye precipitate at the site of β-Gal activity. The dimerization and oxidation reaction is facilitated, in this kit, by a developer buffer solution containing ferric and ferrous ions. Both transfection efficiency and comparative expression levels can be determined by examining and counting the number of blue cells in the total cell population.

 

This kit is sold by Marker Gene under product code M1352.