Marjorie Longo, UC Davis; Steve Boxer, Stanford University
Phase separated supported lipid bilayers were chemically imaged by HR-SIMS performed with the NanoSIMS 50 (Cameca Instruments). A focused Cs+ ion beam is rastered across the sample, extensively fragmenting the surface components. Secondary ions of up to 5 different masses are simultaneously detected and a lateral resolution of 50 nm can be achieved. In our experiments, a unique stable isotope was selectively incorporated into each membrane component, and the intensity and location of the isotopically enriched secondary ions were used to create a component-specific image of the phase separated lipid bilayer.