5-Bromo-4-chloro-3-indolyl-β-D-galactoside (X-Gal)research grade

C14H15BrClNO6Mr 408.6CAS [7240-90-6]

X-Gal is a well known histochemical substrate used to detect the β-galactosidase enzyme (1, 2, 3, 4, 9, 10). Identification of lacf-colonies (8). X-gal is used to distinguish recombinant plasmids from parental vectors in cloning experiments using vectors containing the lacZ or lacZ [DMvP1](-)peptide gene (2, 3, 5). Upon hydrolysis, X-Gal yields a localized, insoluble blue precipitate making it exceptionally useful in blotting, immunocytochemical, and ELISA assays. X-Gal has been used for the detection of coliforms (E. coli) in municipal water supplies (6) and food products (7). X-Gal is often used in conjunction with IPTG (Isopropyl-β-D-thiogalactopyranoside, cat. no. 26600) which binds and inhibits the lac repressor thus inducing β-galactosidase activity.
Stock solution: 20 mg/ml in DMF. Store in aliquots at -20 °C in the dark. For detection of transformants, use in final concentration of 40 µg/ml.

Purity (HPLC)
min. 99.0 %

  1. Maloy, S.R. (1990) Experimental Techniques in Bacterial Genetics, Jones and Bartlett (eds.), Boston, MA
  2. Miller, J.H.(1992) A Short Course in Bacterial Genetic, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.
  3. Sambrook, J. et al. (1989) Molecular Cloning: A laboratory Manual, 2nd. ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor (4.8, 4.22-4.23, 4.33, 4.37-4.38, 1.85-1.86, B.14)
  4. Horowitz, J. et al. (1964) J. Med. Chem. 7, 574
  5. Brand, A. and Perrimon, N. (1993), Development 118, 401
  6. Ley, A. et al. (1993) Can. J. Microbio. 39, 821
  7. Feldsine, P.T. et al. (1993) J. AOAC Int. 76, 5
  8. Lojda, Z. et al. (1973) Histochemie 34, 31-9
  9. Lojda, Z. et al. (1979) in »Enzyme Histochemistry, A Laboratory Manual«, Springer-Verlag Berlin, Heidelberg, New York
  10. . Davies et al. (1980) Advanced Bacterial Genetics, Cold Spring Harbor, N.Y.
EINECS: 230-640-8WGK: 1HS: 29389090
Storage Temperature: +2 °C to +8 °C

250 mg
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