title: Direct imaging of single cells and tissue at sub-cellular spatial resolution using transmission geometry MALDI MS.
abstract: The need of cellular and sub-cellular spatial resolution in laser desorption ionization (LDI)/matrix-assisted LDI (MALDI) imaging mass spectrometry (IMS) necessitates micron and sub-micron laser spot sizes at biologically relevant sensitivities, introducing significant challenges for MS technology. To this end, we have developed a transmission geometry vacuum ion source that allows the laser beam to irradiate the back side of the sample. This arrangement obviates the mechanical/ion optic complications in the source by completely separating the optical lens and ion optic structures. We have experimentally demonstrated the viability of transmission geometry MALDI MS for imaging biological tissues and cells with sub-cellular spatial resolution. Furthermore, we demonstrate that in conjunction with new sample preparation protocols, the sensitivity of this instrument is sufficient to obtain molecular images at sub-micron spatial resolution.
authors.affiliation: National Research Resource for Imaging Mass Spectrometry and Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 7232-8575, USA.
authors.forename: Andre
authors.initials: A
authors.lastname: Zavalin
authors.forename: Erik M
authors.initials: EM
authors.lastname: Todd
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Rawhouser
authors.forename: Junhai
authors.initials: J
authors.lastname: Yang
authors.forename: Jeremy L
authors.initials: JL
authors.lastname: Norris
authors.forename: Richard M
authors.initials: RM
authors.lastname: Caprioli
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D004867:Equipment Design; D057809:HEK293 Cells; D006652:Histological Techniques / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008055:Lipids / Q000032:analysis / Q000737:chemistry; D051379:Mice; D057054:Molecular Imaging / Q000295:instrumentation / Q000379:methods*; D011506:Proteins / Q000032:analysis / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D059010:Single-Cell Analysis / Q000295:instrumentation / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*
chemical_list: D008055:Lipids; D011506:Proteins