Next-Generation Imaging Mass Spectrometry

March 2, 2021

This Monday afternoon session brings together five young leaders in the field of mass spectrometry (MS) to discuss cutting-edge developments in imaging MS technologies. These presentations will be of interest to practitioners of metabolomics, proteomics, imaging, fundamental ion chemistry, and biomedical analyses, as well as the analytical community at large.

The session will kick off at 1:30 pm with a talk by Kristin Burnum-Johnson of the Pacific Northwest National Laboratory on MS imaging of over 2000 proteins from tissue sections at better than 100-µm spatial resolution using nanodroplet processing in one pot for trace samples (nanoPOTS) sample preparation. To address several challenges of the using of imaging MS on tissue sections, Burnum-Johnson and her associates developed an integrated imaging MS platform that combines laser capture microdissection, nanoPOTS sample preparation, nanoLC–MS/MS, and an open-source bioinformatic tool for data processing and visualization. This platform can quantitatively generate cell-type-specific images for >2000 proteins at 100-µm spatial resolution across 12-µm thick tissue sections using a label free quantitation approach.

Next, at 2:05 pm, Livia Eberlin of the University of Texas at Austin will discuss intraoperative molecular analysis in vivo using the MasSpec Pen technology. The results obtained in this study show that the MasSpec Pen system can be successfully incorporated into the operating room, allowing direct detection of rich molecular profiles from tissues with a seconds-long turnaround time that could be transformative to inform surgical and clinical decisions without major disruptions to clinical and tissue analysis workflows.

Boone Prentice of the University of Florida will then describe, at 2:40 pm, high chemical resolution imaging using gas-phase ion–ion reactions. Prentice and associates have enabled gas-phase charge inversion ion–ion reactions on a hybrid Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. This technology has enabled the identification of multiple stereospecifically numbered (sn)-positional isomers directly from mouse brain tissue, and has also been used to separate isobaric lipids as well as concentrate ion signal from hydrogen, sodium, and potassium ion types.

This will be followed by a talk at 2:30 by Jens Soltwisch of the University of Munster on the use of matrix-assisted laser desorption/ionization (MALDI) with laser post-ionization to enable sensitive MS imaging at high spatial resolution. With this label-free technique, full mass spectra are generated pixel-by-pixel from a matrix-coated surface (such as a tissue section), with the help of a finely focused laser allowing to visualize the spatial distribution of up to hundreds of analyte species simultaneously. Soltwisch will present selected examples including tissue sections interest and single-cell analysis from cell culture.

The session will wrap up with a talk at 4:05 pm by Jeffrey Spraggins of Vanderbilt University on high-performance MS for advanced multimodal molecular imaging. This presentation will highlight Spraggins’s team’s work developing new, high-performance technologies for improving spatial resolution, sensitivity, and specificity of MALDI IMS, including ithe development of post-ionization strategies for improved sensitivity and the utilization of high mass resolution FT-ICR MS and trapped ion mobility spectrometry (TIMS) to address the molecular complexity associated with direct tissue analysis. Recent advances in integrated, multimodal methods that enable molecular signals to be paired to specific biological tissue features will be described and demonstrated through applications that include understanding the molecular drivers of host-pathogen interactions and the construction of comprehensive molecular atlases of human tissues.

Link to the full session: