ROS in bacterial populations have been evaluated with fluorescent dyes using plate readers or by measuring mean fluorescence intensity (MFI) in total cell populations collected using flow cytometer.
You can refer to the article attached for the method.
The generation of ROS was determined using fluorogenic dye 20, 70-
dichlorofluorescein diacetate (DCFDA). About 1 mL of culture suspensions from pathogens with
cell load of 1x108 CFU mL-1
was taken into various test tubes and 2.5 μL of DCFDA solution was added. All the reaction tubes were incubated in shaker under dark condition for
25 min at 37°C. Prepared antimicrobial substance (eg.Au NPs) was added to each test tube and again 2 h incubated in dark condition. The ROS formed in the sample after 2 h was
detected at 488/525 nm of fluorescence excitation/emission intensity measured using