Targeted multiplex imaging mass spectrometry utilizes several different antigen-specific primary antibodies, each directly labeled with a unique photocleavable mass tag, to detect multiple antigens in a single tissue section. Each photocleavable mass tag bound to an antibody has a unique molecular weight and can be readily ionized by laser desorption ionization mass spectrometry. This article describes a mass spectrometry method that allows imaging of targeted single cells within tissue using transmission geometry laser desorption ionization mass spectrometry. Transmission geometry focuses the laser beam on the back side of the tissue placed on a glass slide, providing a 2 μm diameter laser spot irradiating the biological specimen. This matrix-free method enables simultaneous localization at the sub-cellular level of multiple antigens using specific tagged antibodies. We have used this technology to visualize the co-expression of synaptophysin and two major hormones peptides, insulin and somatostatin, in duplex assays in beta and delta cells contained in a human pancreatic islet.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3624063 | PMC |
http://dx.doi.org/10.1007/s13361-012-0563-z | DOI Listing |
Int Endod J
January 2025
Department of Restorative Dentistry-Endodontics, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, São Paulo, Brazil.
Aim: Calcium silicate-based cements have been widely used in dentistry mainly due to their physicochemical and biological properties. Commercially available materials use radiopacifiers containing metals (bismuth, tantalum, tungsten and/or zirconium). To investigate volumetric changes, in vivo biocompatibility and systemic migration from eight commercially available materials, including powder/liquid and 'ready-to-use' presentations.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Analytic Biochemistry, Calculi and Manual Chemistry, Mass Spectrometry, ARUP Laboratories, Inc., Salt Lake City, UT, USA.
Metanephrines (metanephrine [MN] and normetanephrine [NMN]) are O-methylated metabolites derived from the catecholamines, epinephrine, and norepinephrine, respectively. High concentrations of metanephrines have been observed in individuals with pheochromocytoma, a neuroendocrine tumor. Measurement of metanephrines in urine is used to screen for the tumor.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Department of Food Quality and Nutrition, Research and Innovation Center, Fondazione Edmund Mach, San Michele all'Adige, Italy.
The final aim of metabolomics is the comprehensive and holistic study of the metabolome in biological samples. Therefore, the use of instruments that enable the analysis of metabolites belonging to various chemical classes in a wide range of concentrations is essential, without compromising on robustness, resolution, sensitivity, specificity, and metabolite annotation. These characteristics are crucial for the analysis of very complex samples, such as wine, whose metabolome is the result of the sum of metabolites derived from grapes, yeast(s), bacteria(s), and chemical or physical modification during winemaking.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Department of Medicine and Surgery, Proteomics and Metabolomics Unit, University of Milano-Bicocca, Vedano al Lambro, Italy.
Trapped ion mobility spectrometry (TIMS) using parallel accumulation serial fragmentation (PASEF) is an advanced analytical technique that offers several advantages in mass spectrometry (MS)-based lipidomics. TIMS provides an additional dimension of separation to mass spectrometry and accurate collision cross-section (CCS) measurements for ions, aiding in the structural characterization of molecules. This is especially valuable in lipidomics for identifying and distinguishing isomeric or structurally similar compounds.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Laboratory of Analytical Biochemistry & Metabolomics, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.
A simple analytical workflow is described for gas chromatographic-mass spectrometric (GC-MS)-based chiral profiling of secondary amino acids (AAs) in biological matrices. The sample preparation is carried out directly in aqueous biological sample extracts and involves in situ heptafluorobutyl chloroformate (HFBCF) derivatization-liquid-liquid microextraction of nonpolar products into hexane phase followed by subsequent formation of the corresponding methylamides from the HFB esters by direct treatment with methylamine reagent solution. The (O, N) HFB-butoxycarbonyl-methylamide AA products (HFBOC-MA) are separated on a Chirasil-L-Val capillary column and quantitatively measured by GC-MS operated in selected ion monitoring (SIM) mode.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!