@article{sohn_kibbe_dioli_hector_bai_garrard_muddiman_2024, title={A statistical approach to system suitability testing for mass spectrometry imaging}, volume={38}, ISSN={["1097-0231"]}, DOI={10.1002/rcm.9725}, abstractNote={RationaleMass spectrometry imaging (MSI) elevates the power of conventional mass spectrometry (MS) to multidimensional space, elucidating both chemical composition and localization. However, the field lacks any robust quality control (QC) and/or system suitability testing (SST) protocols to monitor inconsistencies during data acquisition, both of which are integral to ensure the validity of experimental results. To satisfy this demand in the community, we propose an adaptable QC/SST approach with five analyte options amendable to various ionization MSI platforms (e.g., desorption electrospray ionization, matrix‐assisted laser desorption/ionization [MALDI], MALDI‐2, and infrared matrix‐assisted laser desorption electrospray ionization [IR‐MALDESI]).}, number={9}, journal={RAPID COMMUNICATIONS IN MASS SPECTROMETRY}, author={Sohn, Alexandria L. and Kibbe, Russell R. and Dioli, Olivia E. and Hector, Emily C. and Bai, Hongxia and Garrard, Kenneth P. and Muddiman, David C.}, year={2024}, month={May} }
 @article{wang_sohn_samal_erning_segura_muddiman_2023, title={Lipidomic Analysis of Mouse Brain to Evaluate the Efficacy and Preservation of Different Tissue Preparatory Techniques by IR-MALDESI-MSI}, volume={3}, ISSN={["1879-1123"]}, DOI={10.1021/jasms.2c00353}, abstractNote={Numerous preparatory methods have been developed to preserve the cellular and structural integrity of various biological tissues for different -omics studies. Herein, two preparatory methods for mass spectrometry imaging (MSI) were evaluated, fresh-frozen and sucrose-embedded, paraformaldehyde (PFA) fixed, in terms of ion abundance, putative lipid identifications, and preservation of analyte spatial distributions. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI)-MSI was utilized to compare the preparatory methods of interest with and without the use of the conventional ice matrix. There were 2.5-fold and 1.6-fold more lipid species putatively identified in positive- and negative-ion modes, respectively, for sucrose-embedded, PFA-fixed tissues without an ice matrix relative to the current IR-MALDESI-MSI gold-standard, fresh-frozen tissue preparation with an exogenous ice matrix. Furthermore, sucrose-embedded tissues demonstrated improved spatial distribution of ions resulting from the cryo-protective property of sucrose and paraformaldehyde fixation. Evidence from these investigations supports sucrose-embedding without ice matrix as an alternative preparatory technique for IR-MALDESI-MSI.}, journal={JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY}, author={Wang, Mary F. and Sohn, Alexandria L. and Samal, Juhi and Erning, Kevin and Segura, Tatiana and Muddiman, David C.}, year={2023}, month={Mar} }
 @article{xi_sohn_joignant_cologna_prentice_muddiman_2023, title={SMART: A data reporting standard for mass spectrometry imaging}, volume={58}, ISSN={["1096-9888"]}, DOI={10.1002/jms.4904}, abstractNote={Abstract}, number={2}, journal={JOURNAL OF MASS SPECTROMETRY}, author={Xi, Ying and Sohn, Alexandria L. and Joignant, Alena N. and Cologna, Stephanie M. and Prentice, Boone M. and Muddiman, David C.}, year={2023}, month={Feb} }
 @article{sohn_ping_glass_seyfried_hector_muddiman_2022, title={Interrogating the Metabolomic Profile of Amyotrophic Lateral Sclerosis in the Post-Mortem Human Brain by Infrared Matrix-Assisted Laser Desorption Electrospray Ionization (IR-MALDESI) Mass Spectrometry Imaging (MSI)}, volume={12}, ISSN={["2218-1989"]}, DOI={10.3390/metabo12111096}, abstractNote={Amyotrophic lateral sclerosis (ALS) is an idiopathic, fatal neurodegenerative disease characterized by progressive loss of motor function with an average survival time of 2–5 years after diagnosis. Due to the lack of signature biomarkers and heterogenous disease phenotypes, a definitive diagnosis of ALS can be challenging. Comprehensive investigation of this disease is imperative to discovering unique features to expedite the diagnostic process and improve diagnostic accuracy. Here, we present untargeted metabolomics by mass spectrometry imaging (MSI) for comparing sporadic ALS (sALS) and C9orf72 positive (C9Pos) post-mortem frontal cortex human brain tissues against a control cohort. The spatial distribution and relative abundance of metabolites were measured by infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) MSI for association to biological pathways. Proteomic studies on the same patients were completed via LC-MS/MS in a previous study, and results were integrated with imaging metabolomics results to enhance the breadth of molecular coverage. Utilizing METASPACE annotation platform and MSiPeakfinder, nearly 300 metabolites were identified across the sixteen samples, where 25 were identified as dysregulated between disease cohorts. The dysregulated metabolites were further examined for their relevance to alanine, aspartate, and glutamate metabolism, glutathione metabolism, and arginine and proline metabolism. The dysregulated pathways discussed are consistent with reports from other ALS studies. To our knowledge, this work is the first of its kind, reporting on the investigation of ALS post-mortem human brain tissue analyzed by multiomic MSI.}, number={11}, journal={METABOLITES}, author={Sohn, Alexandria L. and Ping, Lingyan and Glass, Jonathan D. and Seyfried, Nicholas T. and Hector, Emily C. and Muddiman, David C.}, year={2022}, month={Nov} }