Characterization of theo-IS14. (A) The ON/OFF induction ratios of theo-IS14 at various concentrations of theophylline. Inset: Expansion at low concentrations. (B) Relative fluorescence intensities and images of YPet expressed from DNA templates encoding theo-IS14 or m-theo-IS14 before the YPet gene (T7-theo-IS14-Y or T7-m-theo-IS14-Y, respectively) in the absence or presence of 1 mM theophylline (theo) or caffeine (caf) in the WGE-cIVTT system. The leftmost lane is the positive control (PC-DNA-Y). A schematic of the mutations in m-theo-IS14 is also shown. (C) Relative luminescence intensities and images of nLuc expressed from the DNA template encoding theo-IS14 before the nLuc gene (T7-theo-IS14-nL) in the absence or presence of 1 mM theophylline in the WGE-cIVTT system. The error bars represent the standard deviation (n = 4).
