Liquid-liquid phase coexistence in lipid membranes observed by natural abundance 1 H- 13 C solid-state NMR.

We demonstrate that H-1-C-13 solid-state MAS NMR is suitable to detect liquid disordered/liquid ordered phase coexistence in a DOPC/DPPC/cholesterol mixture with natural abundance of isotopes as an alternative to H-2 NMR. Such methodology is potentially applicable to study lipid phase coexistence phenomena in biological matter with high lipid content, e.g. lung surfactant or myelin, for which isotopic labeling is not possible.