title: Precast Gelatin-Based Molds for Tissue Embedding Compatible with Mass Spectrometry Imaging.
abstract: Preparation of tissue for matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) generally involves embedding the tissue followed by freezing and cryosectioning, usually between 5 and 25 μm thick, depending on the tissue type and the analyte(s) of interest. The brain is approximately 60% fat; it therefore lacks rigidity and poses structural preservation challenges during sample preparation. Histological sample preparation procedures are generally transferable to MALDI-MSI; however, there are various limitations. Optimal cutting temperature compound (OCT) is commonly used to embed and mount fixed tissue onto the chuck inside the cryostat during cryosectioning. However, OCT contains potential interferences that are detrimental to MALDI-MSI, while fixation is undesirable for the analysis of some analytes either due to extraction or chemical modification (i.e., polar metabolites). Therefore, a method for both fixed and fresh tissue compatible with MALDI-MSI and histology is desirable to increase the breadth of analyte(s), maintain the topographies of the brain, and provide rigidity to the fragile tissue while eliminating background interference. The method we introduce uses precast gelatin-based molds in which a whole mouse brain is embedded, flash frozen, and cryosectioned in preparation for mass spectrometry imaging (MSI).
authors.affiliation: Department of Chemistry, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Emily L
authors.initials: EL
authors.lastname: Gill
authors.affiliation: Department of Chemistry, University of Florida , Gainesville, Florida 32611, United States.|Department of Pathology, Immunology and Laboratory Medicine, University of Florida , Gainesville, Florida 32610, United States.
authors.forename: Richard A
authors.identifier: 0000-0002-1293-5669
authors.initials: RA
authors.lastname: Yost
authors.affiliation: Department of Neurosurgery, University of Florida , Gainesville, Florida 32610, United States.
authors.forename: Vinata
authors.initials: V
authors.lastname: Vedam-Mai
authors.affiliation: Department of Pathology, Immunology and Laboratory Medicine, University of Florida , Gainesville, Florida 32610, United States.
authors.forename: Timothy J
authors.identifier: 0000-0003-1623-009X
authors.initials: TJ
authors.lastname: Garrett
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001921:Brain / Q000166:cytology; D005780:Gelatin; D051379:Mice; D057054:Molecular Imaging / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D016610:Tissue Embedding / Q000379:methods*
chemical_list: D001672:Biocompatible Materials; D005780:Gelatin