Convenience for blue/white screening The b-galactosidase substrate X-Gal (5-bromo-4-chloro-3-indolyl-b-D-galactopyranoside) is a chromogenic stain for b-gal activity, and is commonly used to distinguish between recombinants and nonrecombinants by lacZ a-complementation with appropriate vectors and hosts. X-Gal Solution is provided as a convenient 40 mg/ml concentrate in DMSO, ready for dilution into culture medium or appropriate buffers. | 
