Figure 3.

Efflux of minocycline and doxycycline from loaded neutrophils. Cells were loaded to a steady-state intracellular concentration by incubation for 15 minutes at 37°C in HBSS containing 30 μg/ml minocycline or doxycycline. Efflux was triggered by diluting the extracellular antimicrobial solutions 1:20 with 37°C HBSS and monitored by the decrease in cell-associated fluorescence.