Spatial mapping of membrane phases in confluent endothelial cells

Endothelial cells (ECs) form the inner lining, of the blood vasculature and are therefore exposed to blood borne molecules and hemodynamic forces which exact potent changes in EC biology. The EC plasma membrane transduces molecular and mechanical signals through membrane proteins which are sensitive to the lipid phase state surrounding them. We describe a method for high spatial resolution mapping of membrane phase states using molecular spectroscopic measurements of fluorescence lifetimes and polarizations of phase-specific lipoid dyes. The role of membrane phases in signal transduction is discussed.