title: Homogeneous matrix deposition on dried agar for MALDI imaging mass spectrometry of microbial cultures.
abstract: Matrix deposition on agar-based microbial colonies for MALDI imaging mass spectrometry is often complicated by the complex media on which microbes are grown. This Application Note demonstrates how consecutive short spray pulses of a matrix solution can form an evenly closed matrix layer on dried agar. Compared with sieving dry matrix onto wet agar, this method supports analyte cocrystallization, which results in significantly more signals, higher signal-to-noise ratios, and improved ionization efficiency. The even matrix layer improves spot-to-spot precision of measured m/z values when using TOF mass spectrometers. With this technique, we established reproducible imaging mass spectrometry of myxobacterial cultures on nutrient-rich cultivation media, which was not possible with the sieving technique. Graphical Abstract ᅟ.
authors: Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA, 92093, USA. thomas.hoffmann@helmholtz-hzi.de.|Department of Pharmaceutical Biotechnology, Saarland University and Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, 66123, Saarbrücken, Germany. thomas.hoffmann@helmholtz-hzi.de.
authors: Thomas
authors: T
authors: Hoffmann
authors: Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA, 92093, USA.
authors: Pieter C
authors: PC
authors: Dorrestein
mesh_terms: D000362:Agar / Q000737:chemistry*; D001419:Bacteria / Q000737:chemistry*; D001431:Bacteriological Techniques / Q000379:methods*; D057054:Molecular Imaging / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D000362:Agar
keywords: MALDI; Matrix application; Microbial IMS; Myxobacteria; Natural products