Raw experimental data (UV, CD, NMR and gel electrophoresis) collected for the set of 64 DNA sequences of the type 5'-GGT1-4GGT1-4GGT1-4GG-3' in presence of K+ ions.

The provided dataset is divided into five subfolders containing: 1) “CD” – raw circular dichroism data in text format 2) “Electrophoresis” - Raw gel images collected on the Typhoon phosphorimager - for all 64 sequences in presence of K+ and in presence of Li+ for a selected subset 3) “1D_NMR” – raw and processed 1D NMR data corresponding to three sets of measurements – a) at reference conditions (150 mM KCl, 0.4 mM DNA), b) with either DNA or KCl diluted ten-fold, c) after solvent exchange to D2O 4) “2D_NMR” – raw and processed 2D NMR data for the 17 DNA sequences for which G-quadruplex loop topologies were successfully assigned 5) “UV” – raw UV melting curves collected at 295 nm