Abstract:

During the past few years, our lab has developed a wide range of methods for patterning lipid bilayers on solid supports [Accts. Chem. Res. 35, 149 (2002)].  These 2D fluids are interesting both as a model for biological membranes and as a physical system with unusual properties.  Methods have been developed for controlling the composition of patterned membrane corrals by variations on microcontact printing and microfluidics. Charged components can be moved around within these fluid surfaces by a form of 2D electrophoresis.  The planar geometry of supported bilayer systems is ideal for high resolution imaging methods.  Advances using optical interferometry and mass spectrometry will be described.  Variable angle total internal fluorescence microscopy (VIA-TIRFM) and variable angle fluorescence interference contrast (VIA-FLIC) can provide information on the z position of fluorescent objects with sub-nm resolution.  VIA-FLIC is particularly well suited for measuring complex objects such as cells, and prospects for this method will be discussed.  The lateral (x-y) composition of membranes can be analyzed by high spatial resolution secondary ion mass spectrometry (SIMS) using the NanoSIMS.  Results will be described for simple membrane compositions and phase separated domains suggesting the potential of this method for the analysis of membrane organization in complex membranes.