Search term Cloning Reagent has been found in the following products: 7

Cloning Reagent

X-Gal, 5-Bromo-4-chloro-3-indolyl β-D-galactopyranoside, X0320

  • CAS Number : 7240-90-6
  • Formula : C14H15BrClNO6
  • MW : 408.63
  • Purity : ≥ 99% (by HPLC)
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Cat No Size Price
X0320-002 200 mg $ 38.00 Add to cart
X0320-010 1 g $ 70.00 Add to cart
X0320-050 5 g $ 210.00 Add to cart
X0320-101 10 g $ 305.00 Add to cart
X0320-105 50 g $ 1,390.00 Add to cart
Solubility in DMSO/PBS X-Gal should be dissolved in DMSO and then diluted with PBS(PBS 7.2). 0.5mg/ml in a 1:1 solution of DMSO:PBS,
Solubility in DMF 2% in DMF
Application Detect β-galactosidase activity
X-gal is commonly used in conjunction with IPTG for blue-white screening.

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. Bacteria 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.

Many other applications also use X-Gal as a substrate to detect β-galactosidase activity. These include β-galactosidase -antibody linked immunoassays and immunohistochemistry, coliphage detection based on β-galactosidase induction and the detection of micrometastasis formation during tumor progession.