Prodan fluorescence detects the bilayer packing of asymmetric phospholipids

▶ There is no difference in phase-transition quantities between LMV and GMV. ▶ Prodan fluorescence is affected by vesicle size, chain asymmetry and phase state. ▶ Vesicle size markedly affects the packing of the interdigitated gel phase. ▶ 3-D fluorescence imaging by using Prodan is useful to examine the bilayer packing.