Metabolic stable isotope incorporation and secondary ion mass spectrometry (SIMS) depth profiling performed on a Cameca NanoSIMS 50 were used to image the18O-cholesterol and15N-sphingolipid distributions within a portion of a Madin-Darby canine kidney (MDCK) cell. Three-dimensional representations of the component-specific isotope distributions show clearly defined regions of18O-cholesterol and15N-sphingolipid enrichment that seem to be separate subcellular compartments. The low levels of nitrogen-containing secondary ions detected at the18O-enriched regions suggest that these18O-cholesterol-rich structures may be lipid droplets, which have a core consisting of cholesterol esters and triacylglycerides.
ASJC Scopus subject areas
- Materials Science(all)
- Biochemistry, Genetics and Molecular Biology(all)
- Physics and Astronomy(all)