Preparation of stable and solvent-free model membranes.

A method for the preparation of solvent-free, phospholipid-impregnated filters is described. Polycarbonate filters of 13 mm diameter, 5 μm thickness and 0.1 μm pore size were employed, and 20 to 48 nmol phospholipid per filter was incorporated. Passive permeation of polar substances across the filter was determined by a flow-dialysis procedure. The presence of phospholipid led to a decrease in passive permeability by 96 – 99%. Due to their size and stability, and a partially preferential lipid orientation, these phospholipid-impregnated filters may serve as an alternative type of model membrane.