nuclear Overhauser enhancement spectroscopy saturation transfer difference nuclear magnetic resonance spectroscopy STD nuclear magnetic resonance saturation transfer difference spectroscopy STD-NMR spectroscopy STD-NMR A type of NMR spectroscopy where radio frequency pulses are used to induce an equal population of upper and lower spin states in ('saturate') certain selected protons, removing their signal from the NMR spectrum. The resulting spectrum is then subtracted from a reference spectrum obtained without saturation. Saturation-transfer NMR is used to detect the transient binding of small molecule ligands to macromolecular receptors. CHMO:0000897 nuclear magnetic resonance saturation transfer difference (STD) spectroscopy saturation transfer difference (STD) nuclear magnetic resonance spectroscopy