title: Matrix-free mass spectrometric imaging using laser desorption ionisation Fourier transform ion cyclotron resonance mass spectrometry.
abstract: Mass spectrometry imaging (MSI) is a powerful tool in metabolomics and proteomics for the spatial localization and identification of pharmaceuticals, metabolites, lipids, peptides and proteins in biological tissues. However, sample preparation remains a crucial variable in obtaining the most accurate distributions. Common washing steps used to remove salts, and solvent-based matrix application, allow analyte spreading to occur. Solvent-free matrix applications can reduce this risk, but increase the possibility of ionisation bias due to matrix adhesion to tissue sections. We report here the use of matrix-free MSI using laser desorption ionisation performed on a 12 T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. We used unprocessed tissue with no post-processing following thaw-mounting on matrix-assisted laser desorption ionisation (MALDI) indium-tin oxide (ITO) target plates. The identification and distribution of a range of phospholipids in mouse brain and kidney sections are presented and compared with previously published MALDI time-of-flight (TOF) MSI distributions.
authors.affiliation: Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8QQ, UK. Richard.goodwin@glasgow.ac.uk
authors.forename: Richard J A
authors.initials: RJ
authors.lastname: Goodwin
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Pitt
authors.forename: David
authors.initials: D
authors.lastname: Harrison
authors.forename: Stefan K
authors.initials: SK
authors.lastname: Weidt
authors.forename: Pat R R
authors.initials: PR
authors.lastname: Langridge-Smith
authors.forename: Michael P
authors.initials: MP
authors.lastname: Barrett
authors.forename: C
authors.initials: C
authors.lastname: Logan Mackay
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D005583:Fourier Analysis; D006651:Histocytochemistry / Q000379:methods*; D007668:Kidney / Q000737:chemistry; D055432:Metabolomics; D051379:Mice; D010743:Phospholipids / Q000032:analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D017971:Tin Compounds
chemical_list: D010743:Phospholipids; D017971:Tin Compounds; C109984:indium tin oxide