Stability of bilayer lipid membranes on different metallic supports

In order to arrive at an optimized s-BLM protocol, the influence of various metallic supports (silver, iridium and stainless steel) of different diameters (from 0.14 to 0.33 mm) on the process of forming and stability of supported phospholipid bilayer membranes was studied. In addition, experiments were made using different membrane-forming solutions, ionic strength and pH. The transmembrane resistance and the current ratio between bare and lipid-coated wire at +670 mV were measured. Teflon-coated stainless steel support (0.33 mm in diameter) covered with 2% crude ox brain fraction of phospholipids was most convenient for the formation of supported bilayer lipid membranes on solid support. The well-known stabilizing effect of cholesterol was confirmed for the s-BLM system. Both the pH in the range 5.0-8.0 (silver and stainless steel supports) and the ionic strength (for all types of supports) in the range from 0.025 to 0.1 mol/l at pH 7.0 were found not to be crucial.