Lipids often are labile, unstable, and tend to degrade overtime, so it is of the upmost importance to study these molecules in their most native state. We sought to understand the optimal storage conditions for spatial lipidomic analysis of human kidney tissue sections. Specifically, we evaluated human kidney tissue sections on several different days throughout the span of a week using our established protocol for elucidating lipids using high mass resolution matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). We studied kidney tissue sections stored under five different conditions: open stored at -80 °C, vacuumed sealed and stored at -80 °C, with matrix preapplied before storage at -80 °C, under a nitrogen atmosphere and stored at -80 °C, and at room temperature in a desiccator. Results were compared to data obtained from kidney tissue sections that were prepared and analyzed immediately after cryosectioning. Data was processed using METASPACE. After a week of storage, the sections stored at room temperature showed the largest amount of lipid degradation, while sections stored under nitrogen and at -80 °C retained the greatest number of overlapping annotations in relation to freshly cut tissue. Overall, we found that molecular degradation of the tissue sections was unavoidable over time, regardless of storage conditions, but storing tissue sections in an inert gas at low temperatures can curtail molecular degradation within tissue sections.

中文翻译：

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人肾组织切片的储存条件影响空间脂质组学分析的重现性。

脂质通常不稳定、不稳定，并且会随着时间的推移而降解，因此研究这些处于最天然状态的分子至关重要。我们试图了解人类肾脏组织切片空间脂质组学分析的最佳储存条件。具体来说，我们使用我们建立的使用高质量分辨率矩阵辅助激光解吸/电离质谱成像 (MALDI-MSI) 阐明脂质的既定方案，在一周的不同日子里评估了人体肾脏组织切片。我们研究了在五种不同条件下储存的肾组织切片：在 -80 °C 下开放储存，在 -80 °C 下抽真空密封储存，在 -80 °C 储存前预涂基质，在氮气气氛下储存在 -80 °C C，并在室温下置于干燥器中。将结果与从冷冻切片后立即制备和分析的肾组织切片获得的数据进行比较。使用 METASPACE 处理数据。储存一周后，在室温下储存的切片显示出最大量的脂质降解，而在氮气和 -80 °C 下储存的切片保留了最多数量的与新鲜切割组织相关的重叠注释。总的来说，我们发现随着时间的推移，组织切片的分子降解是不可避免的，无论储存条件如何，但在低温惰性气体中储存组织切片可以减少组织切片内的分子降解。在室温下储存的切片显示出最大量的脂质降解，而在氮气和 -80 °C 下储存的切片保留了与新鲜切割组织相关的最大数量的重叠注释。总的来说，我们发现随着时间的推移，组织切片的分子降解是不可避免的，无论储存条件如何，但在低温惰性气体中储存组织切片可以减少组织切片内的分子降解。在室温下储存的切片显示出最大量的脂质降解，而在氮气和 -80 °C 下储存的切片保留了与新鲜切割组织相关的最大数量的重叠注释。总的来说，我们发现随着时间的推移，组织切片的分子降解是不可避免的，无论储存条件如何，但在低温惰性气体中储存组织切片可以减少组织切片内的分子降解。