Single-Cell, Time-Lapse Reactive Oxygen Species Detection in E. coli.

Detection of reactive oxygen species (ROS) in bacteria has been limited to bulk biochemical assays. Although they are powerful and quantitative tools to understand the overall production of ROS in E. coli, such assays provide limited spatial and temporal information when correlating cellular phenotype with perturbations such as antibiotics or other treatments. We have developed single-cell, time-lapse assays to detect ROS in live E. coli. The assays utilize flow systems on a fluorescence microscope to correlate symptoms aroused from biological or chemical perturbations with the in situ detection of ROS. ROS is detected by fluorogenic dyes that accumulate inside the cell, allowing detection of ROS in single cells in both homogeneous and heterogeneous samples using CellROX Green and Amplex® Red/APEX2.