Differential capacitance, chronocoulometry and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) measurements were used to characterize the structure and orientation of DMPC + cholesterol (70:30 mol%.,) phospholipid bilayers prepared using combined Langmuir-Blodgett/Langmuir-Schaefer (LB/LS) deposition. The electrochemical measurements indicate that incorporation of cholesterol into the membrane improves the quality of the bilayer if both leaflets contain cholesterol. Phospholipid bilayers containing DMPC and cholesterol prepared using LB/LS deposition were found to have smaller tilt angles (similar to 27 degrees) than bilayers prepared by vesicle spreading (similar to 52 degrees), indicating that LB/LS deposition is a superior method for preparing supported phospholipid bilayers at a gold electrode surface. (c) 2007 Elsevier B.V. All rights reserved.