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Several years ago, it was demonstrated convincingly (1-3) that ‘H-detected chemicalshift correlation via heteronuclear multiple-quantum coherence (HMQC)(3-5) offers a substantial sensitivity advantage over the conventional shift-correlation experiment (6-9), in which the low-y nucleus is detected directly during the data acquisition period. The ‘H-detected HMQC experiment, however, has not yet gained the popularity one might expect on the basis of its intrinsic advantages. Major problems with the HMQC experiment are the dynamic range problem that is introduced by the presence of large signals from protons that are not coupled to the low-y nucleus and the required suppression of these intense signals in a difference experiment. In principle, both problems can be solved by presaturating the proton signals and transferring the NOE-enhanced low-y signal to the protons (IO), but the sensitivity advantage of the ‘H …