The thermotropic transition of large unilamellar (LUV) vesicles of dimyristoyl phosphatidylcholine by Raman spectroscopy

Abstract By observing Raman spectra in the 2800–3000 cm −1 region, we determined the gel to liquid transition characteristics of large unilamellar vesicles of dimyristoyl phosphatidylcholine. This transition occurs between 22°C and 28.5°C. The large unilamellar vesicles can be well distinguished from the small unilamellar vesicles, which gel to liquid transition is spread out from 10°C to 27°C. The multilamellar vesicles on the other hand melt in a highly cooperative phenomenon at 23.7°C. The intermediate character of the transition of large unilamellar vesicles is also illustrated by data of the lateral order parameter.