High-Resolution Secondary Ion Mass Spectrometry for Chemically Imaging Cell Membrane Organization

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

With support from the Chemical Measurement and Imaging Program (CMI) in the Division of Chemistry (CHE) and the Cellular Dynamics and Function Cluster in the Division of Molecular and Cellular Biosciences (MCB), Professor Mary Kraft and her group at University of Illinois at Urbana-Champaign are developing new approaches to quantitatively image the subcellular distribution of distinct lipid species. Differences in the relative abundances of cholesterol among the membranes of various organelles influence mammalian cell function and are correlated with disease. Yet, current analytical tools are inadequate for assessing the cholesterol abundance within subcellular compartments. Professor Kraft and her team plan to address this need by developing a high-resolution secondary ion mass spectrometry method for quantitatively imaging cholesterol and sphingolipids within specific cellular organelles with high spatial resolution. This work entails the development and optimization of labeling strategies for organelle detection, depth profiling conditions, and quantitative data analysis methods, as well as determination of sputtering rates on mammalian cells. The proposed research will yield a chemically specific approach for imaging the relative abundances of cholesterol and other lipid species in specific organelles or near intracellular proteins of interest with less than 100-nm-lateral resolution. This chemical imaging tool will greatly facilitate identifying the mechanisms by which cholesterol regulates intracellular trafficking, and ultimately, cellular function. The project will train graduate and undergraduate students in secondary ion mass spectrometry, cell biology, metabolism, quantitative bioanalytical chemistry, experimental design and hypothesis testing. Results will be incorporated into a lecture and laboratory activity that will be presented at the Girls' Adventures in Mathematics, Engineering, and Science (GAMES) Bio- and Chemical Engineering Camp for 9th and 10th grade young women.