title: Preservation of ultrastructure in phosphatidylcholine vesicles by tannic acid and OsO4.
abstract: To improve preservation and visualization of membrane structure in artificial phosphatidylcholine vesicles (PC liposomes), the following three fixation formulas including tannic acid (TA) and osmium (OsO4) steps were tested: (1) TA-OsO4, (2) OsO4-TA, and (3) OsO4-TA-OsO4. The TA-OsO4 method, known to stabilize PC against conventional dehydration, was inadequate for characterizing liposome structure because it induced a serious artifact that the liposomes were aggregated and fused. On the other hand, the OsO4-TA method did not cause the artifact but only a dull EM image was obtained for the membrane structure. The best results with egg PC liposomes have been obtained by the OsO4-TA-OsO4 method which gives improved preservation and enhanced contrast of membrane structure.
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine; D002784:Cholesterol; D004134:Dimyristoylphosphatidylcholine; D047348:Hydrolyzable Tannins; D008081:Liposomes; D008854:Microscopy, Electron; D008954:Models, Biological; D008968:Molecular Conformation; D009993:Osmium Tetroxide; D010713:Phosphatidylcholines
chemical_list: D047348:Hydrolyzable Tannins; D008081:Liposomes; D010713:Phosphatidylcholines; D015060:1,2-Dipalmitoylphosphatidylcholine; D002784:Cholesterol; D009993:Osmium Tetroxide; D004134:Dimyristoylphosphatidylcholine