Small-angle neutron scattering from large unilamellar vesicles: An improved method for membrane thickness determination

Small-angle neutron scattering (SANS) measurements were performed on large unilamellar vesicles (LUVs) in order to investigate solute effects on membrane properties. Although SANS is a well established technique for the measurement of membrane thickness in unilamellar vesicles, earlier measurements have depended on approximate treatments of the scattering function and have suffered from effects of multilamellarity or difficulty in sample preparation. More recent studies of temperature induced thickness changes in DPPC LUVs which have included explicit treatment of the full scattering function were complicated by disparities between the predicted and measured scattering curves. Here, we reexamine theoretical descriptions of SANS from LUVs. Motivated by our observations, we then introduce a new method for interpretation of SANS data, which we compare to established techniques and apply to our measurements.