Determination of line tension in lipid monolayers by Fourier analysis of capillary waves.

In the past decade, intense interest has focused on the phase separation and lateral organization of two-dimensional lipid systems. In this manuscript, we describe a method for extracting the interfacial line tension between coexisting monolayer phases through direct observations of thermal fluctuations using fluorescence microscopy and digital image processing. We demonstrate that the interfacial line tension calculated from the capillary wave spectrum is in good agreement with previous measurements employed using other experimental techniques.