Figure 5: Taq polymerase stop assay at increasing K+ concentrations.

(a) Oligonucleotides were folded in the absence or presence of K+ (50–100 mM). Oligonucleotides were used as templates in a Taq polymerase reaction at 37 °C. Stop regions corresponding to LTR-III are indicated by the *symbol, to LTR-II by § and to LTR-IV by#. P indicates the band of the labelled primer. M is a marker lane obtained with the Maxam & Gilbert sequencing protocol. (b) Quantification of lanes 1–10 of panel (a). Quantification of stop bands corresponding to formation of LTR-II and LTR-III G4s and of the full-length amplification product (FL) is shown.