NMR studies of membrane and other hydrophobic / lipophilic proteins often require the use of a lipid or lipid-like detergent to maintain solubility and stability. However, this can create NMR signal interference from the increased concentration of hydrogen atoms added by the densely packed detergent. By replacing the hydrogen atoms in the detergent with a per deuterated equivalent, you can silence the interference and make it easier to resolve the protein structure.