The preparation of extended and highly organized, very thin layers of polymers has been an area of intense research interest and is of great relevance to the production of a new generation of ion- selective electrodes having totally nonconventional geometries. One particularly successful method to obtain large area, ultrathin polymer monolayers is through polymerization of lipid molecules at the gas/water interface. Polymerized lipid monolayers produced with diacetylenes have been shown to be remarkably rigid, while those with dienoyl are much more flexible. Other work has shown that the addition of gramicidin to some types of lipid films can control the rate of polymerization. The experiments planned for the Phase I program involve ion conductance measurements on gramidicin-containing polymerized lipid monolayers of diacetylene and dienoyl. A comparison of both types of monolayers will provide insight into the effect of monolayer rigidity on gramicidin channel function. Added control over the molecular packing density will be attempted by using either fatty alcohols and/or fatty acids as the polymerized lipids. The functional reconstitution of polypeptide channels has never been attempted before in a polymerized lipid monolayer where a high degree of film density can be obtained.