Experimental determination of lipid fluidity
31P NMR experiments can be used to determine the phase and
to estimate the mobility of lipids. Highly mobile chains are in
rapid exchange and give narrow NMR lines. Lipids in the gel
state (crystalline state) have ordered acyl chains with little mobility so that the NMR lines become broad.
Each phase (bilayer, hexagonal, vesicle) has a characteristic
Other techniques for determining the diffusion rates in lipid phases include fluorescent labeling and electron spin