Membrane Interferometry

A long-range goal in our lab is to merge two well-known types of measurements – single channel recording and Fluorescence Interference Contrast (FLIC) microscopy to correlate structure and function in ion channels or other integral membrane proteins reconstituted into model lipid membranes.  This combination of approaches, applied to single channels, has never been achieved.  FLIC and a variable incidence angle variation we developed (VIA-FLIC) can provide information on the position of a fluorophore relative to a surface with nm or even sub-nm precision [230, 233].  We call a device that can achieve this a “membrane interferometer”.  Our first design (shown upper right) was able to achieve very high resolution, but we were unable to insert electrodes to perform electrophysiological measurements [265].  A more recent design (shown lower right) allows for the incorporation of electrodes and combined optical and electrophysiological measurements are in progress.

[265] "A Membrane Interferometer", Prasad Ganesan and Steven Boxer, PNAS, 106, 14, 5627-5632, (2009). [pdf][Supplement]