Mass spectrometry imaging (MSI) has evolved as a significant tool to map biomolecules in situ without tags. This chapter describes advancements in mass spectrometry imaging technology and applications focused on mapping cholesterol. Secondary ion mass spectrometry (SIMS), matrix-assisted laser desorption/ionization (MALDI), and desorption electrospray (DESI) modes are described. These MSI technologies range in spatial resolution, and therefore different levels of mapping ranging from intracellular to whole tissue can be achieved. A variety of technical examples showing methods for cholesterol and cholesterol-derived molecular imaging are provided as well as imaging results from membrane dynamics, and genetic and drug treatment models. This emerging application of MSI for mapping cholesterol in biological specimens provides a new means to gain a deeper understanding of cholesterol distribution, and thereby insights into function.
Keywords: Cholesterol; Isotope; Label-free imaging; Mapping; Mass spectrometry.