Isotope-edited NMR experiments ( 91JMC2937 , 00PROG323 ) have been shown to be very useful for studying inter- and intramolecular interactions in macromolecular complexes in which one of the two components is usually labeled with ¹³C and/or ¹⁵N isotopes. An isotope filter usually selects/rejects the magnetization which originated solely from one of the two components. Thus, the resulting spectrum only contains a reduced number of resonances and, therefore, are amenable to a more detailed spectral analysis ( 94METH657 , 94METH700 , 94METH717 , and 94METH739 ).

Several Labeling strategies are feasible:

Isotope-filtered experiments detect ¹H signals attached to ¹²C/¹⁴N nuclei and remove ¹³C/¹⁵N-attached ¹H signals

Isotope-edited (isotope-separated) experiments detect ¹H signals attached to ¹³C/¹⁵N nuclei and remove ¹²C/¹⁴N-attached ¹H signals for selective observation of interactions between ¹³C/¹⁵N isotope-labeled and unlabeled molecules.

General Reading: B03ZER373