IPTG (isopropylthio-β-galactoside), a structural non-metabolizable analogue of allolactose, is an inducer of β-galactosidase activity in bacteria and is suitable for use with X-Gal or Bluo-Gal to detect lac gene activity in cloning procedures. IPTG binds to the lac repressor, releasing it from the lac operator, and thereby allowing the transcription of genes in the lac operon, such as the gene coding for β-galactosidase.
In addition, IPTG is one of the most efficient molecular inducers for promoter’s transcriptional activity and is used extensively for heterologous protein expression induction in E. coli. Though mainly used in cell culture assays, publications demonstrated the use IPTG in vivo in animal models too.
Primary applications
• Blue-white screening—induce functional β-galactosidase
• Induce protein expression from inducible T7 RNA polymerase E. coli expression systems egulated by lac operon