Dynamic staining of bacteria at a single-cell level

Bacterial infectious diseases remain one of the major health hazards nation- and worldwide. The expedience of detection and identification of bacterial pathogens determines how early the diagnosis is, and hence, what the treatment and the outcome of the illness would be. As we have previously reported, the dynamics of fluorescence staining provides venues for the development of expedient assays for detection and identification of bacterial species[1]. We measured the kinetics of bacterial staining with cyanine and thioflavin dyes and investigated their photophysical properties. We demonstrated that the pseudo first-order kinetic constants of the fluorescence staining processes have species specificity without contrition dependence. Combining the dynamics of staining with real-time fluorescence microscopy we characterized the fluorescence staining process at the single-cell level with improved sensitivity and contrast.