A general assignment method for oriented sample (OS) solid-state NMR of proteins based on the correlation of resonances through heteronuclear dipolar couplings in samples aligned parallel and perpendicular to the magnetic field

► Heteronuclear dipolar couplings differ by two in perpendicular and parallel bilayers. ► Dipolar couplings correlate resonances in perpendicular and parallel bilayers. ► Assignments result from the dipolar correlation and an assigned isotropic spectrum.