Figure 3.

Characterization of the AST platform using the quality control strain. (A) Kinetic measurements of cell viability via oxygen-sensing nanoprobes immobilized in the agarose gel matrix. Comparison between control without antibiotic (no ATB) supplement E. coli ATCC 25922 culture (red, n = 15), and cultivation in the presence of ciprofloxacin at three different concentrations: 0.25 MIC_ref, 1 MIC_ref, and 4 MIC_ref (green; numbers of analyzed chambers: n = 15, 24, 66, and 42, respectively). (B) Figures of the individual chambers show the bacterial morphology at the end of the measurement for each concentration of ciprofloxacin, MIC_ref = 0.008 μg mL^–1. Scale bars: 100 μm. Temperature: 37 °C; MHB II, cation-adjusted medium and an initial OD₆₀₀ of 0.02 were maintained in all experiments. Error bars represent the standard deviations.