Regions of the 1D ¹H NMR spectra of d(CGCGT⁵GCG) acquired at 600 MHz showing characteristic resonances associated with the hairpin loop form of the molecule. (a) Unmodified octamer under salt-free condition at a concentration of 1.0 mM [Reference Data] (b) Unmodified octamer immediately prior to the addition of I (c) Unmodified octamer immediately following the addition of I (d) Phosphorothioate modified octamer immediately following the addition of I. “h” indicates the presence of a hairpin form of the octamer. For (c) and (d), additional resonances labelled * were ascribed to an alternative structural form.