Effect of the lipid concentration dissolved in mineral oil on liposome lamellarity. In all experiments, egg PC containing 0.1% (mol/mol) rhodamine PE was used. (A) Average number of liposomes found in the observation chamber per 50 fields of view (0.031 mm2 × 50 = 1.55 mm2) was plotted against the lipid concentration dissolved in oil. Clear spherical-shaped liposomes with a diameter larger than 2 μm were counted. We performed at least three independent experiments, and averaged these results for each lipid concentration. Error bars indicate the SD. (B) Lamellarity distributions of the liposomes prepared at different lipid concentrations. The percentages of unilamellar liposomes in preparations containing 0.5, 5, and 10 mM lipid were compared with that prepared with 1 mM egg PC by the χ2test and Fisher’s exact test. n.s.: not significant (p > 0.05), ∗∗p < 0.01.