Lipids in cell walls are continually under attack from reactive oxygen species (ROS). It has been suggested that the presence of oxidized lipids influences the tendency of lipid mixtures to form rafts, something that could have major biological consequences. In this work we propose to study the effects of oxidation on the formation and stability of lipid rafts. We will form monolayers of a ternary lipid mixture known to form rafts and exposure the monolayer to an oxidant, ozone gas, thus forming an oxidized monolayer in situ. We will follow changes to the composition of the monolayer using specular neutron reflection combined with selective deuteration, and changes to the formation and stability of lipid rafts (order domains) using off-specular neutron reflection.