{"entity": "researcher", "timestamp": "2026-10-01T12:34:18.126Z", "family": "Dexter", "given": "Alex", "initials": "A", "orcid": "0000-0001-8536-4417", "affiliations": ["National Centre of Excellence in Mass Spectrometry Imaging (NiCE-MSI) , National Physical Laboratory , Teddington TW11 0LW , U.K."], "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/researcher/157c6e94e7db457f9da942af544e89bf.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/researcher/157c6e94e7db457f9da942af544e89bf"}}, "publications": [{"entity": "publication", "iuid": "1bd25ff86cd64d19bbd3b8a3e2cec4aa", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/1bd25ff86cd64d19bbd3b8a3e2cec4aa.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/1bd25ff86cd64d19bbd3b8a3e2cec4aa"}}, "title": "Quantitation of Endogenous Metabolites in Mouse Tumors Using Mass-Spectrometry Imaging.", "authors": [{"family": "Swales", "given": "John G", "initials": "JG", "orcid": "0000-0002-4792-0037", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/8e5150f58ae14d8aaa5f7f47470935ee.json"}}, {"family": "Dexter", "given": "Alex", "initials": "A", "orcid": "0000-0001-8536-4417", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/157c6e94e7db457f9da942af544e89bf.json"}}, {"family": "Hamm", "given": "Gregory", "initials": "G"}, {"family": "Nilsson", "given": "Anna", "initials": "A"}, {"family": "Strittmatter", "given": "Nicole", "initials": "N"}, {"family": "Michopoulos", "given": "Filippos", "initials": "F"}, {"family": "Hardy", "given": "Christopher", "initials": "C"}, {"family": "Morentin-Gutierrez", "given": "Pablo", "initials": "P"}, {"family": "Mellor", "given": "Martine", "initials": "M"}, {"family": "Andren", "given": "Per E", "initials": "PE", "orcid": "0000-0002-4062-7743", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/f1dd27e8b238475383983480e10099f6.json"}}, {"family": "Clench", "given": "Malcolm R", "initials": "MR"}, {"family": "Bunch", "given": "Josephine", "initials": "J"}, {"family": "Critchlow", "given": "Susan E", "initials": "SE"}, {"family": "Goodwin", "given": "Richard J A", "initials": "RJA"}], "type": "journal article", "published": "2018-05-15", "journal": {"title": "Anal. Chem.", "issn": "1520-6882", "volume": "90", "issue": "10", "pages": "6051-6058", "issn-l": "0003-2700"}, "abstract": "Described is a quantitative-mass-spectrometry-imaging (qMSI) methodology for the analysis of lactate and glutamate distributions in order to delineate heterogeneity among mouse tumor models used to support drug-discovery efficacy testing. We evaluate and report on preanalysis-stabilization methods aimed at improving the reproducibility and efficiency of quantitative assessments of endogenous molecules in tissues. Stability experiments demonstrate that optimum stabilization protocols consist of frozen-tissue embedding, post-tissue-sectioning desiccation, and storage at -80 \u00b0C of tissue sections sealed in vacuum-tight containers. Optimized stabilization protocols are used in combination with qMSI methodology for the absolute quantitation of lactate and glutamate in tumors, incorporating the use of two different stable-isotope-labeled versions of each analyte and spectral-clustering performed on each tissue section using k-means clustering to allow region-specific, pixel-by-pixel quantitation. Region-specific qMSI was used to screen different tumor models and identify a phenotype that has low lactate heterogeneity, which will enable accurate measurements of lactate modulation in future drug-discovery studies. We conclude that using optimized qMSI protocols, it is possible to quantify endogenous metabolites within tumors, and region-specific quantitation can provide valuable insight into tissue heterogeneity and the tumor microenvironment.", "doi": "10.1021/acs.analchem.7b05239", "pmid": "29668267", "labels": [], "xrefs": [], "notes": [], "created": "2018-12-05T12:39:55.126Z", "modified": "2026-09-23T08:31:14.171Z"}]}