7240-90-6,X-gal,5-Bromo-4-chloro-3-indolyl-beta-D-galactoside,
CAS:7240-90-6
C14H15BrClNO6 / 408.63
MFCD00005666
5-溴-4-氯-3-吲哚基-β-D-吡喃半乳糖苷
X-Gal is a cell-permeable, chromogenic substrate for β-galactosidase that is used in histochemical and molecular biology applications, including detection of lacZ activity in cells and tissues. It generates an indigo-colored precipitate as an indication of enzymatic activity.
5-bromo-4-chloro-3-indolyl beta-D-galactoside is an indolyl carbohydrate that is the beta-D-galactoside of 3-hydroxy-1H-indole in which the indole moiety is substituted at positions 4 and 5 by chlorine and bromine, respectively. It is used to test for the presence of an enzyme, beta-galactosidase, which cleaved the glycosidic bond to give 5-bromo-4-chloro-3-hydroxy-1H-indole, which immediately dimerises to give an intensely blue product. It has a role as a chromogenic compound. It is an indolyl carbohydrate, a beta-D-galactoside, an organochlorine compound, an organobromine compound and a D-aldohexose derivative.
X-Gal is a chromogenic substrate for β-galactosidase, yielding a blue precipitate. X-Gal is an indicator for coliforms in culture media, as well as for the detection of coliforms (E. coli ) in municipal water supplies and food products. X-Gal can be used in conjuction with the inducer IPTG, which binds and inhibits the lac repressor thus inducing β-galactosidase expression. X-Gal is the substrate of choice for blue-white selection of recombinant bacterial colonies with the lac+ genotype.
Upon hydrolysis, X-Gal yields a localized, insoluble, blue precipitate, making it exceptionally useful in blotting, immunocytochemical, and ELISA assays. 5-Bromo-4-chloro-3-indoxyl-β-D-galactopyranoside (X-β-D-galactoside, X-Gal) is a chromogenic indicator for β-galactosidase activity. The colorless product is cleaved by lactose-utilizing bacteriain liquid media or on agar plates and yields a blue-green colored precipiate.
X-Gal can also be used as a detecting agent for β-galactosidase activity in reporter gene assays or for identification of positive transformants on agar plates when using the α-complementation approach. Color formation is due to dimerization and oxidation of 5-bromo-4-chloro-3-hydroxyindole which results from enzymatic cleavage of X-Gal. The reaction proceeds only in the presence of oxygen, i.e. in aerobiccultures. Well detectable color bacterial colonies or liquid cultures is obtained within 16-48 h. In the presence of purified β-galactosidase, color develops within minutes to few hours.
Title: X-gal
CAS Registry Number: 7240-90-6
CAS Name: 5-Bromo-4-chloro-1H-indol-3-yl b-D-galactopyranoside
Molecular Formula: C14H15BrClNO6
Molecular Weight: 408.63
Percent Composition: C 41.15%, H 3.70%, Br 19.55%, Cl 8.68%, N 3.43%, O 23.49%
Literature References: Chromogenic substrate of the lacZ gene product, b-galactosidase; produces a rich blue color when cleaved by the enzyme. Prepn: J. P. Horwitz et al., J. Med. Chem. 7, 574 (1964). Colorimetric reaction in tissue to localize b-galactosidase: B. Pearson et al., Lab. Invest. 12, 1249 (1963); Z. Lojda, Histochemie 23, 266 (1970). Protocol for blue-white a-complementation screening: J. Sambrook et al., Molecular Cloning: A Laboratory Manual (Cold Spring Harbor, New York, 2nd ed., 1989) pp 1.7-1.9, 1.85-1.87. Optimization of detection of exogenous bacterial lacZ expression: D. J. Weiss et al., Hum. Gene Ther. 8, 1545 (1997); of fixative conditions in X-gal staining: W. Ma et al., J. Histochem. Cytochem. 50, 1421 (2002); of blue-white screening procedure: A. L. Sherwood, BioTechniques 34, 644 (2003).
Properties: Amorphous solid from methanol, mp 237-239° (dec). [a]D24 -69° (c = 1.0 in 50% DMF). Sol in DMF, DMSO.
Melting point: mp 237-239° (dec)
Optical Rotation: [a]D24 -69° (c = 1.0 in 50% DMF)
Use: In histochemical staining, in blue-white selection of bacterial colonies with lacZ gene activity during cloning experiments.
CAS Number | 7240-90-6 |
Product Name | 5-Bromo-4-chloro-3-indolyl beta-galactoside |
IUPAC Name | (2S,3R,4S,5R,6R)-2-[(5-bromo-4-chloro-1H-indol-3-yl)oxy]-6-(hydroxymethyl)oxane-3,4,5-triol |
Molecular Formula | C14H15BrClNO6 |
Molecular Weight | 408.63 g/mol |
InChI | InChI=1S/C14H15BrClNO6/c15-5-1-2-6-9(10(5)16)7(3-17-6)22-14-13(21)12(20)11(19)8(4-18)23-14/h1-3,8,11-14,17-21H,4H2/t8-,11+,12+,13-,14-/m1/s1 |
InChI Key | OPIFSICVWOWJMJ-AEOCFKNESA-N |
SMILES | C1=CC(=C(C2=C1NC=C2OC3C(C(C(C(O3)CO)O)O)O)Cl)Br |
Synonyms | 5-bromo-4-chloro-3-indolyl beta-galactoside, 5-bromo-4-chloro-3-indolyl-beta D-galactopyranoside, 5-bromo-4-chloro-3-indolyl-beta-D-galactoside, X-gal |
Canonical SMILES | C1=CC(=C(C2=C1NC=C2OC3C(C(C(C(O3)CO)O)O)O)Cl)Br |
Isomeric SMILES | C1=CC(=C(C2=C1NC=C2O[C@H]3[C@@H]([C@H]([C@H]([C@H](O3)CO)O)O)O)Cl)Br |
COA:
Name: 5-Bromo-4-chloro-3-indolyl-beta-D-galactoside, X-gal
CAS: 7240-90-6 M.F.: C14H15BrClNO6 M.W.: 408.63
Items | Standards | Results |
Appearance | White crystalline power | Positive |
Solubility | Soluble in DMF and insoluble in ether | Positive |
NMR and MS | Should comply | Complies |
Identification | IR and TLC | Positive |
M.P. | 200℃ ~ 230℃ | 205℃ ~230℃ |
[a]20D [C=1 inH2O/DMF 1:1] | -60o ~ -65o | -63.8o |
Loss Weight On Dryness | Max. 1% | Complies |
Alpha-Isomer | Max. 0.5% | 0 |
TLC (15%H2SO4-C2H5OH) | Should be one spot | Complies |
Assay by HPLC | Min. 98% | 99.2% |
References:
1. Weiss DJ, Liggitt D, Clark JG, Human Gene Therapy 1997, 8, 13, p1545-1554
2. Engler KH, et al., J. Microbiol. Methods 1999, 35, p207
3. Arakawa H, et al., Anal. Biochem. 1991, 199, p238
Contact: Miss.Xing
Phone: 18310328607 , 13621067991,13552979007
Tel: 86+10-61274189
Email: chemsynlab@163.com, zhangchao@chemsynlab.com
Add: A411 Room,No.26,Jinyuan Road,Daxing Industrial Developing District,Beijing,China post code:102628