title: Look and see if it is time to induce protein expression in Escherichia coli cultures.
abstract: 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.
authors.affiliation: Department of Biochemistry and Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8725, USA.
authors.forename: K Danielle
authors.initials: KD
authors.lastname: Kelley
authors.forename: Lorenzo Q
authors.initials: LQ
authors.lastname: Olive
authors.forename: Arina
authors.initials: A
authors.lastname: Hadziselimovic
authors.forename: Charles R
authors.initials: CR
authors.lastname: Sanders
mesh_terms: D001391:Azo Compounds; D001431:Bacteriological Techniques / Q000379:methods*; D003001:Cloning, Molecular / Q000379:methods*; D004396:Coloring Agents; D004926:Escherichia coli / Q000166:cytology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D007202:Indicators and Reagents; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D009601:Nitroreductases; D011994:Recombinant Proteins / Q000096:biosynthesis*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D007202:Indicators and Reagents; D011994:Recombinant Proteins; D007544:Isopropyl Thiogalactoside; C008492:methyl red; D009247:NADH, NADPH Oxidoreductases; D009601:Nitroreductases; C021106:azoreductase