Figure 1.

Scheme showing the experimental setup used for studying bacterial colonization of cell layers. A once-through flow-setup is applied with sterile media (A) pumped through the flow chamber (B) using a high-precision peristaltic pump located downstream of the flow chamber (C). The flow chamber is placed on a computer-controlled, motorized stage under the microscope (D), allowing image recording of the infected cell layer (E). Predetermined locations on the cell layer (F) are monitored by time-lapse phase-contrast and fluorescence microscopy, with data extracted subsequently and computer-processed into growth curves (G). The entire setup is kept in an incubator to control temperature and CO₂ levels.