Sizing of phosphatidylcholine vesicles by transmission electron microscopy

Coating of support films for transmission electron microscopy with silica by evaporation of "silicon monoxide" provides a surface which is easily wetted by aqueous systems. Dispersed colloidal particles spread on this surface without the use of added soluble wetting agents. Such coated supports are found to be particularly useful for the quantitative characterization of the size distribution of vesicles prepared from saturated phosphatidylcholine. The weight average vesicle sizes determined for several samples from measurements of negatively stained electron micrographs are in good agreement with values measured by light scattering and ultracentrifugation.