title: Mass spectrometric imaging of lipids using desorption electrospray ionization.
abstract: Desorption electrospray ionization (DESI), a relatively new ambient ionization technique used in mass spectrometry (MS), allows for the direct analysis of samples such as thin tissue sections, to be conducted outside of vacuum in the ambient environment and often without sample preparation. DESI-MS has been used in order to systematically characterize phospholipids, which are abundant species in biological tissue samples. Lipids play important biological roles and differences in lipid compositions have been seen in diseases such as cancer and Alzheimer's disease. Imaging of thin tissue sections exploits the ability of DESI-MS to study these lipids directly in the biological matrix. In imaging MS (IMS), a mass spectrum is recorded at each pixel while moving the surface containing the sample so that the entire sample area is covered. The information in these mass spectra can be combined to create a 2D chemical image of the sample, combining information on spatial distribution with information on chemical identity from the characteristic ions in the mass spectra. DESI-MS has been used to image a variety of tissue samples including human liver adenocarcinoma, rat brain, human breast tissue and canine abdominal tumor tissue. Comparisons between diseased and normal tissue are made in these studies.
authors.affiliation: Department of Chemistry and Center for Analytical Instrumentation Development, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Allison L
authors.initials: AL
authors.lastname: Dill
authors.forename: Demian R
authors.initials: DR
authors.lastname: Ifa
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Manicke
authors.forename: Zheng
authors.initials: Z
authors.lastname: Ouyang
authors.forename: R Graham
authors.initials: RG
authors.lastname: Cooks
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D001940:Breast / Q000737:chemistry; D004285:Dogs; D006801:Humans; D008055:Lipids / Q000737:chemistry*; D008099:Liver / Q000737:chemistry; D008968:Molecular Conformation; D009369:Neoplasms / Q000737:chemistry; D051381:Rats; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D008055:Lipids