 A more specific example of this case is presented in the section "Chemical Exchange Magnetization transfer".In either case, magnetization transfer techniques probe the dynamic relationship between two or more distinguishable nuclei populations, in so far as energy exchange between the populations can be induced and measured in an idealized NMR experiment.In magnetic resonance imaging or NMR of macromolecular samples, such as protein solutions, at least two types of water molecules, free (bulk) and bound (hydration), are present.