50 - 100 msec
||Bacteria Escherichia coli
||Ullman G, Wallden M, Marklund EG, Mahmutovic A, Razinkov I, Elf J. High-throughput gene expression analysis at the level of single proteins using a microfluidic turbidostat and automated cell tracking. Philos Trans R Soc Lond B Biol Sci. 2012 Dec 24 368(1611):20120025. doi: 10.1098/rstb.2012.0025. p.1 2nd paragraphPubMed ID23267179
||P.2 left column top paragraph:"In this study, [investigators] report on a method combining microfluidics, single-molecule fluorescence microscopy and automated image analysis, enabling the study of the expression and super-resolution localization of low copy number transcription factors throughout thousands of bacterial lifespans per experiment. To illustrate the performance of the method, [they] quantify the dynamics of synthesis and intracellular localization of the lactose repressor by monitoring LacI–Venus expressed from its native promoter in live E. coli cells. [They] compare these observations with those obtained under identical conditions for cells expressing the reporter construct Tsr–Venus from the lactose permease gene, lacY, of the lactose operon."
||p.1 2nd paragraph:"For instance, Yu et al. [ref 3] reported on the use of a fast maturing yellow fluorescent protein (YFP) variant, Venus [ref 4], fused to a membrane tag, Tsr, to profile the absolute expression of the lacZ gene, in live Escherichia coli cells, in its repressed state. The Tsr domain immobilizes the fluorophore at the membrane so that it appears stationary for periods of 50–100 ms and can be detected as a diffraction-limited spot."