Fig. 6
Comparison between the fluorescent signal acquired with the microscope setup and the one obtained with the flow cytometer. In a the dose response curve for the tested gene circuit is reported. There is a very good agreement between the results obtained with our set-up (red dots) and those of the flow cytometer (blue dots), with only minor discrepancies at the lower induction levels. In b the accordance between the data acquired with the two instruments is analyzed through a correlation graph. The relation is linear (green line, R 2 > 0.99) and the SEs are comparable, demonstrating the ability of our set-up in capturing, at the single cell level, the average fluorescence intensity emitted by a population of bacteria. A quadratic function fits better the relation between the two datasets at the beginning of the dynamic range, likely due to the higher sensitivity of the flow cytometer (MSE = 7.6x 10-5). The equations of the green line and of the parabola that fit the data points are reported below. Fluomicro = 1.15 Fluocyto -0.16, Fluomicro = 0.44 Fluocyto 2 + 0.55 Fluocyto + 0.02