Surface Plasmon Microscopy of Two Crystalline Domains in a Lipid Monolayer

Surface plasmon microscopy is applied to monolayers of dimyristoylphosphatidylethanolamine,dipcast at high lateral pressure (35 mN/m) on a solid substrate. The vertical resolution of better than 1 nm and an in-plane resolution of - 10 um allow for the detection of two separate solid domains. Assuming a fixed value for the lipid refractive index, the tilt angles of the lipid aliphatic chains were determined to be 0° and -35°, respectively.