isopropyl-thiogalactoside and methyl-red

It is shown that Methyl Red can be used as an indicator dye that changes color in Escherichia coli culture as a result of time- and cell density-dependent bleaching by azoreductase produced by the bacteria. For cell cultures that are being used to express a recombinant protein, this phenomenon can be exploited to provide a simple visual cue that cell cultures have reached an appropriate growth phase for addition of an agent to induce protein expression, such as isopropyl thiogalactoside.

Topics: Azo Compounds; Bacteriological Techniques; Cloning, Molecular; Coloring Agents; Escherichia coli; Gene Expression Regulation; Indicators and Reagents; Isopropyl Thiogalactoside; NADH, NADPH Oxidoreductases; Nitroreductases; Recombinant Proteins