Fusion of dipalmitoylphosphatidylcholine vesicles

Small unilamellar dipalmitoylphosphatidylcholine vesicles formed by sonication are shown to fuse spontaneously below the phase transition temperature. The ultimate fusion products are unilamellar vesicles about 700 A in diameter, which are stable and provide an intact ionic permeation barrier either above or below the phase transition. The fused vesicles have been characterized by gel chromatography, trapped volume, 31P nuclear magnetic resonance, and negative stain and freeze-fracture electron microscopy.