Amphiphile-induced spherical microexovesicle corresponds to an extreme local area difference between two monolayers of the membrane bilayer

It is shown that an increase of the area difference between the outer and t he inner membrane lipid layers of the skeleton-free membrane segment as a r esult of exogenously added amphiphilic molecules results in budding of the segment. The process reaches its final point when the segment attains the s hape of the local maximal area difference, corresponding to formation of a spherical microexovesicle.