Single-cell measurement of plasmid copy number and promoter activity

Accurate measurements of promoter activities are crucial for predictably building genetic systems. Here we report a method to simultaneously count plasmid DNA, RNA transcripts, and protein expression in single living bacteria. From these data, the activity of a promoter in units of RNAP/s can be inferred. This work facilitates the reporting of promoters in absolute units, the variability in their activity across a population, and their quantitative toll on cellular resources, all of which provide critical insights for cellular engineering. A quantitative assessment of promoter function can improve the precision of cellular engineering. Here the authors develop a method to simultaneously count plasmid DNA, RNA transcripts and protein expression in single living bacteria.

Automated summary

Accurate measurements of promoter activities are crucial for predictably building genetic systems. This study reports a method to simultaneously count plasmid DNA, RNA transcripts, and protein expression in single living bacteria to infer promoter activity in units of RNAP/s. This quantitative assessment can improve the precision of cellular engineering.