title: Mass imaging and identification of biomolecules with MALDI-QIT-TOF-based system.
abstract: Imaging mass spectrometry is becoming a popular visualization technique in the medical and biological sciences. For its continued development, the ability to both visualize and identify molecules directly on the tissue surface using tandem mass spectrometry (MSn) is essential. We established an imaging system based on a matrix-assisted laser/desorption ionization quadrupole ion trap time-of-flight type instrument (AXIMA-QIT, Shimadzu, Kyoto, Japan), which was compatible with both imaging and highly sensitive MSn. In this paper, we present the operating conditions of the AXIMA-QIT as an imaging instrument and introduce the data converter we developed that is available free of charge. The converted data can be applied to Biomap, the commonly used visualization software. For the feasibility experiments, we demonstrated the visualization of phospholipids, glycolipid, and tryptic-digested proteins in the mouse cerebellum. The visualized lipids were successfully identified by MSn directly on the tissue surface, with a strong ability to isolate precursor ions. In the analysis of tryptic-digested proteins, we compared the product ion spectra between AXIMA-QIT and a tandem TOF-type instrument. The results confirmed that AXIMA-QIT can provide a high quality of product ion spectra even on the tissue surface.
authors.affiliation: Okazaki Institute for Integrative Bioscience, National Institute of Natural Sciences, Okazaki, Aichi 444-8787, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Shimma
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sugiura
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hayasaka
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Zaima
authors.forename: Mineo
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Setou
mesh_terms: D000818:Animals; D002531:Cerebellum / Q000737:chemistry*; D006017:Glycolipids / Q000032:analysis*; D051379:Mice; D010446:Peptide Fragments / Q000032:analysis*; D010743:Phospholipids / Q000032:analysis*; D011506:Proteins / Q000378:metabolism; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014357:Trypsin / Q000378:metabolism
chemical_list: D006017:Glycolipids; D010446:Peptide Fragments; D010743:Phospholipids; D011506:Proteins; D014357:Trypsin