The Gram negative bacterial outer membrane protects the bacterium from external toxins such as antibiotics. This is partially responsible for Gram negative bacteria becoming the greatest emerging source of antibiotic resistance. We are developing models of these bacterial outer membranes and have successfully recreated the characteristic lipid asymmetry (with lipopolysaccharide (LPS) on the outer leaflet and phospholipids on the inner) and also the water filled periplasm. In order to fully recreate the membranes we will need to incorporate more complex LPS versions to mimic pathogenic bacteria. We will incorporate LPS containing one or two O antigens into the final model at different densities to determine who much it increases the bilayer thickness. In future experimental programmes we aim to increase the LPS length to investigate how very long LPS behave.