Evaluating the optimal tissue thickness for mass spectrometry imaging using infrared matrix-assisted laser desorption electrospray ionization.

Autor: Joignant AN; FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, North Carolina, USA., Knizner KT; FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, North Carolina, USA., Xi Y; FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, North Carolina, USA., Muddiman DC; FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, North Carolina, USA.
Jazyk: angličtina
Zdroj: Rapid communications in mass spectrometry : RCM [Rapid Commun Mass Spectrom] 2023 Nov 30; Vol. 37 (22), pp. e9638.
DOI: 10.1002/rcm.9638
Abstrakt: Rationale: Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) utilizes a 2970 nm mid-IR laser to desorb samples with depth resolutions (Z) on the order of micrometers. Conventionally, 5-20 μm thick tissue sections are used to characterize different applications of the IR-MALDESI source, but an optimal thickness has not been systematically investigated.
Methods: Mouse liver was sectioned to various thicknesses and analyzed using IR-MALDESI mass spectrometry imaging (MSI). Height profiles of tissue sections of various cryosectioned thicknesses were acquired to affirm tissue thickness. Tissue sections of each thickness were measured using a Keyence microscope. Paraffin wax was cryosectioned, mounted on microscope slides, and measured using a chromatic confocal sensor system to determine the cryostat sectioning accuracy.
Results: Analyzing sectioned tissues at higher thickness (>10 μm) leads to lower ion abundance, a decrease in signal over long analysis times, and more frequent instrument cleaning. Additionally, increasing tissue thickness above the optimum (7 μm) does not result in a significant increase in lipid annotations.
Conclusions: This work defines an optimal sample thickness for IR-MALDESI-MSI and demonstrates the utility of optimizing tissue thickness for MSI platforms of comparable Z resolution.
(© 2023 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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