We have recently improved the stability and coverage of free standing bilayers (FSB) by the use of a supporting thiolipid layer on gold. The system has been investigated on POLREF and supports the use of magnetic contrast reflectometry. One use for this system is to contribute to our longer term plans to make models of bacterial outer membranes in which a periplasm separates the outer and inner membranes. We have already incorporated the outer membrane protein OmpF into phospholipid membranes and demonstrated the formation of lipopolysaccharide monolayers at the air-water interface. In July 2012 on POLREF we will make FSB with LPS in the outer layer and phospholipid in the inner. This proposal seeks to complete the story by combining our previous work to make an asymmetric mixed OmpF ¿LPS outer membrane model which can be used to investigate the action of antibacterial molecules. .