Andersen Maria K, Giampà Marco, Midtbust Elise, Høiem Therese S, Krossa Sebastian, Tessem May-Britt
Department of Circulation and Medical Imaging, NTNU - Norwegian University of Science and Technology, Trondheim, Norway.
Department of Clinical and Molecular Medicine, NTNU - Norwegian University of Science and Technology, Trondheim, Norway.
Methods Mol Biol. 2023;2688:135-146. doi: 10.1007/978-1-0716-3319-9_12.
Metabolites reflect the biological state of cells and tissue, and metabolomics is therefore a field of high interest both to understand normal physiological functions and disease development. When studying heterogeneous tissue samples, mass spectrometry imaging (MSI) is a valuable tool as it conserves the spatial distribution of analytes on tissue sections. A large proportion of metabolites are, however, small and polar, making them vulnerable to delocalizing through diffusion during sample preparation. Here we present a sample preparation method optimized to limit diffusion and delocalization of small polar metabolites in fresh frozen tissue sections. This sample preparation protocol includes cryosectioning, vacuum frozen storage, and matrix application. The methods described were primely developed for matrix-assisted laser desorption/ionization (MALDI) MSI, but the protocol describing cryosectioning and vacuum freezing storage can also be applied before desorption electrospray ionization (DESI) MSI. Our vacuum drying and vacuum packing approach offers a particular advantage to limit delocalization and safe storage.
代谢物反映了细胞和组织的生物学状态，因此，代谢组学对于理解正常生理功能和疾病发展来说是一个备受关注的领域。在研究异质性组织样本时，质谱成像（MSI）是一种很有价值的工具，因为它能保留组织切片上分析物的空间分布。然而，很大一部分代谢物体积小且具有极性，这使得它们在样品制备过程中容易因扩散而发生移位。在此，我们展示了一种经过优化的样品制备方法，以限制新鲜冷冻组织切片中小极性代谢物的扩散和移位。该样品制备方案包括冷冻切片、真空冷冻保存和基质应用。所描述的方法主要是为基质辅助激光解吸/电离（MALDI）MSI开发的，但描述冷冻切片和真空冷冻保存的方案也可在解吸电喷雾电离（DESI）MSI之前应用。我们的真空干燥和真空包装方法在限制移位和安全保存方面具有独特优势。
