Fluid phospholipid bilayers partially bound to a supporting polymer cushion (tethered supported membranes) have been widely discussed as model systems for studying biomembrane structure and function. Sire have synthesized a new isothiocyanstte-functionalized lipid from dimyristoylphosphatidylethanolamine, which closely resembles naturally occurring membrane lipids. Monolayers containing the reactive Lipid at the air-water interface covalently bind to the amino functionalities of branched polyethylenimine (PEI) added to the water subphase which could be shown by infrared spectroscopy. At neutral pH, PEI is cationically charged which guarantees the transfer of a polymer-supported lipid monolayer onto a mica substrate during Langmuir-Blodgett deposition. A second layer of pure dimyristoylphosphatidylcholine can be deposited by vesicle adsorption. This system should allow the application of techniques such as the surface forces apparatus (SFA) technique to investigate interbilayer forces, membrane-polymer interactions, and other dynamic membrane properties under near in-vivo conditions.