Figure 4
From: Pitfalls in optical on-line monitoring for high-throughput screening of microbial systems
In-vitro characterization and correction of the influence of different fluorescent proteins on the optical pH signal. (A-C) Dependency of the phase angle as raw signal for pH monitoring from YFP, FbFP and mCherry fluorescence for different pH values. (D) Change of pH calibration curve with varied mCherry fluorescence intensity. (E) Correction of the online pH signal for the cultivation of E. coli expressing mCherry by using fluorescence dependent calibration curves. Cultivation conditions: 48well FlowerPlate with optodes for DOT and pH measurement, VL = 800 μL, n = 1100 rpm, d0 = 3 mm, 37°C, Wilms-MOPS medium with 20 g/L glucose, induction with 0.1 mM IPTG after 6 h (indicated by arrow).