Effect on air(4a) and calcein(4b) encapsulation of various solutes present during the freezing step, Liposomes were made by a procedure analogous to that described for gas-containing liposomes except that calcein was included (at 0.1 mM) in the each of the solutions of mannitol or glycine or PBS and added in the lipid hydration step. Liposome composition: DPPC:DOPC:CH 35:35:30. Under same treatment and pressure, mannitol, glycine and PBS solutions provided 38, 18 and 10 μl of gas encapsulation by 5 mg lipid and 22%, 23% and 17% calcein encapsulation efficency, respectively. Mean +/− SD, n=4. *p<0.05 vs trehalose group, ** p<0.01 vs all other groups.