Fig. 5. Three different techniques to monitor biofilms: GMR sensor (left), confocal fluorescence microscope (middle), and phase contrast microscope (right).

Trimethoprim (final dose of 500x MIC, a–e) and ciprofloxacin (final dose of 300x MIC, f–j) injected at 5 h (dashed line) from the beginning of the experiment and microscopic images are obtained after 10 h (dash dotted line) from the start of the experiments. Confocal microscopic images (b, c and g, h) and phase contrast images (d, e and i, j) are all taken at 10 h from the start of the experiments; c and h, e and j are confocal and phase contrast images of biofilms with antibiotic injected at 5 h from the start of the experiments, respectively; The scale bars in the micrographs are all 10 μm long.