GFP reporter assays
Single colonies of cells carrying the indicated reporter fusions were
inoculated into sterile borosilicate glass tubes 16x125 mm (Fisher
Scientific) containing 2 ml of TSB with appropriate antibiotic to
maintain selection. Cells were grown to a stationary phase overnight.
Pellets were collected and washed twice with PBS and resuspended in the
same buffer. 100 μL of the cell suspension was transferred into a flat
bottom black 96-well plate (Corning). Fluorescence was measured using a
Synergy H1 plate reader (BioTek/Agilent) tuning the monochromator to 485
nm and 535 nm (excitation/emission, respectively). Relative fluorescence
units (RFUs) were calculated by subtracting the fluorescence of plain
PBS and dividing by OD600 to correct for cell density.