  When a cell-sized water droplet, with a diameter of several tens of micro
meter, is placed in oil containing phospholipids, a stable cell-sized vesicle
is spontaneously formed as a water-in-oil phospholipid emulsion (W/O CE) with a
phospholipid monolayer. We transferred the lipid vesicle thus formed in the oil
phase to the water phase across the water/oil interface by micromanipulation,
which suggests that the vesicle is transformed from a phospholipid monolayer as
W/O CE into a bilayer. The lipid vesicle can then be transported back into the
oil phase. This novel experimental procedure may be a useful tool for creating
a model cellular system, which, together with a microreactor, is applicable as
a micrometer-scale biochemical reaction field.
