Cholesterol is an essential lipid that is required for the normal functioning of human cell membranes. We investigated the effects of cholesterol on the phase behavior and lateral organization of lipid
monolayers, a model for biological membranes. As more cholesterol is added to a mixture of the saturated lipid DSPC and the unsaturated lipid DOPC, fractal gel phase domains transition to round
fluid phase domains. We quantified the compositions of the co-existing phases with the NanoSIMS 50L by labeling DSPC with 15N and imaging the monolayers after deposition on a silicon support.
Recorded on CAMECA NanoSIMS 50L at Stanford University. Image courtesy of F. Moss.
F. Moss et al. Atomic Recombination in Dynamic Secondary Ion Mass Spectrometry Probes Distance in Lipid Assemblies: A Nanometer Chemical Ruler. J. Am. Chem. Soc. 138, 51, 16737–16744 (2016).