Figure 1.

Measurement of the fluorescence intensity of individual liposomes prepared by the inverted emulsion method. (A) A schematic illustration of the inverted emulsion method. Water-in-oil droplets were transformed into liposomes by passage through the oil/water interface by centrifugation. (B) Epifluorescence image of a liposome across the equatorial plane. Scale bar: 5 μm. Data shown in (C–G) were obtained from this liposome. (C) Relationship between the cross-sectional areas of the liposome and the frame number scanned on the Z axis. The frame that had the maximum area was determined to be the equatorial plane, and is shown as frame number 0. (D) Fluorescence intensity (F.I.) profiles of a cross section of the liposome. The position at 0 μm indicates the center of mass. Measurements were performed radially from the center of the mass, every one degree. The intensity profiles at 0°, 60°, and 120° were shown as the examples. (E–G) The membrane fluorescence intensity profile of the liposome, obtained from (D). (E) The peak fluorescence intensity positions in the X-Y plane. The position at (0,0) indicates the center of mass. (F) The peak fluorescence intensity profile against the angle of the radial axis. The average value (black solid line) and the SD (black dashed line) are also shown. (G) Histogram of the membrane fluorescence intensities shown in (F) and the Gaussian fit (black solid line).