Figure 2. Detection of intracellular NO/RNS in S. aureus with DAF-FM diacetate.

Cells harvested from replicate UAMS-17 h static biofilms were resuspended in 1× HBSS containing 5 μM DAF-FM diacetate. After incubation for 1 h at 37 °C, cells were collected by centrifugation, washed, and resuspended in 1× HBSS alone (“untreated”) or 1× HBSS supplemented with 100 μM DEA or 100 μM DEA/NO. Aliquots (200 μl) of each cell suspension were immediately transferred to a 96-well plate, and incubated at 37 °C in a Synergy HT fluorescent plate reader. Fluorescence and OD₆₀₀ measurements were recorded after 30 min, and data were reported as relative fluorescent units (RFU) per OD₆₀₀ of each well. Data represents the average of n=3 independent experiments, error bars = SEM. *statistical significance compared to untreated UAMS-1 (p < 0.05, Tukey Test). The dataset used in this figure was originally published in (Sapp et al., 2014).