Dfhbi 1t

RNA was prepared as described in the previous section with the addition of 100 mM KCl to the transcription reactions to facilitate folding of G quadruplex aptamers. DFHBI-1T was purchased from Lucerna Technologies (USA) and YO3-biotin was purchased as custom synthesis from Apigenex (Czech Republic). Fluorescence measurements were performed on a FluoroMax 4 (Horiba, Jobin Yvon) by excitation of DFHBI-1T and YO3-biotin at 450 nm and 580 nm, respectively. Emissions of DFHBI-1T and YO3-biotin were recorded at 503 nm and 620 nm, respectively. Monochromator slits were set to 5 nm, and integration time was 0.2 s. Measurement during transcription was done for a 58 μl sample of transcription mix containing 100 mM KCl, 30 ng of DNA template, 2 μM DFHBI-1T and 10 μM YO3-biotin. Transcription was started by adding 2 μl NTPs (25 mM each) and measurements were performed every 5 min for 90 min (Supplementary Fig. 28). To compare several constructs, the produced RNA was quantified on denaturing PAGE as described above. Florescence measurement was performed on 60 μl samples with 150 nM RNA incubated at RT for 20 min with 2 μM DFHBI-1T and 10 μM YO3-biotin.