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X-Gal Solution, ready-to-use

Formula: C14H15BrClNO6, Molecular weight: 408.6

Store at 4°C

X-Gal (5-bromo-4-chloro-3-indolyl-beta-D-galacto-pyranoside) is an inert chromogenic substrate for beta-galactosidase which hydrolyzes X-Gal into colorless galactose and 4-chloro-3-brom-indigo, forming an intense blue precipitate.
  
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X-Gal chemical structure

Formula: C14H15BrClNO6 Molecular weight: 408.6

Thermo Scientific X-Gal (5-bromo-4-chloro-3-indolyl-beta-D-galacto-pyranoside) is an inert chromogenic substrate for beta-galactosidase which hydrolyzes X-Gal into colorless galactose and 4-chloro-3-brom-indigo, forming 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 (see Supporting data).

X-Gal Solution, ready-to-use, is stable, 0.22 µm membrane filtered solution formulated for direct use in conjunction with IPTG for blue/white colony screening.

Applications

  • Blue/white colony screening to distinguish recombinant (white) from non-recombinant (blue) colonies (see Reference 1)
  • Visualization of beta-galactosidase reporter gene expression in transfected eukaryotic cells
  • Detection of beta-galactosidase activity in immunological and histochemical procedures

Note

  • Preparation of a 20 mg/mL stock solution in dimethylformamide (DMF) or dimethylsulfoxide (DMSO) is recommended for X-Gal. DMF dissolves some plastic materials. The direct addition of DMF containing solution to plastic Petri dishes should be avoided.
  • DMF is toxic. Allow X-Gal solution containing dimethylformamide to completely dry before plating bacteria on agar plates.
  
Storage Condition4 C
HazardousNo
FormulaC14H15BrClNO6 
Molecular weight408.6
Quality ControlX-Gal is tested by HPLC. Purity of ≥ 99.0% confirmed. Functionally tested in blue/white cloning assay.
StorageX-Gal Solution, ready-to-use is stable for at least 12 months at 4°C or at room temperature in the original dark vial.
Induction of the lacZ gene with IPTG

Induction of the lacZ gene with IPTG

Induction of the lacZ gene with IPTG


References

  1. J. Sambrook, D. W. Russell, Molecular Cloning: A Laboratory Manual (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, ed. 3, 2001), pp. 1.124-1.125, A1.27.