Analysis of DiI-labeled liposomes by flow cytometry. Representative dot plots of DiI-labeled liposomes that are included in the upper right gate (top). Fluorescence was measured in the FL2 (red) channel. Liposomes were prepared with DiI alone (A), PC 100 µL (B), PC 200 µL (C), PE 100 µL (D), PE 200 µL (E), PC 100 µL:PE 100 µL (F), PC 200 µL:PE 100 µL (G), PC 100 µL:PE 200 µL (H), and PC 200 µL:PE 200 µL (I) (shown in the upper right quadrangle). Bar graph shows the average fluorescence intensity of 6 experiments (n = 6) of DiI binding to liposomes prepared with the above PC and PE ratios. The numbers by the side of PE and PC show the lipid volume used to prepare liposomes (µL). ***P < .001; *P < .013. Error bars represent standard error of the mean. SSC-A, side scatter.