Assessment of paraffin removal from prostate FFPE sections using transmission mode FTIR-FPA imaging
Assessment of paraffin removal from prostate FFPE sections using transmission mode FTIR-FPA imaging
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DOI：
10.1039/c3ay41308j
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发表时间：
2014-01-01
影响因子：
3.1
通讯作者：
Gardner, Peter
中科院分区：
文献类型：
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作者：
Hughes, Caryn;Gaunt, Lydia;Gardner, Peter
在光谱病理学界，通常通过振动光谱技术对福尔马林固定石蜡包埋 (FFPE) 组织切片进行生化鉴别分析。在这些实验中，通常需要从组织中除去石蜡。最常见的是使用二甲苯来执行，但也使用其他溶剂，例如己烷。据认为，通过此类溶剂去除未结合的石蜡也会滤出组织天然的脂质，导致一些人认为对脱蜡组织的剩余脂质的任何后续分析可能不可靠。该研究的范围是评估脱蜡方案是否能够证明石蜡能够根据透射模式红外光谱的可检测极限被可靠地去除。在这项研究中，通过监测与亚甲基碳氢化合物相关的振动作为己烷或二甲苯洗涤过程中溶剂浸泡时间的函数，对人类前列腺癌的两个连续 FFPE 切片的特定采样区域进行了分析。研究结果表明，在溶剂中浸泡 5-10 分钟后，与碳氢化合物相关的振动在整个组织中保持相当一致。这表明，虽然游离的、未结合的组织脂质的亚甲基链从组织中浸出（假设在石蜡包埋之前的第一个组织处理阶段），但耐溶剂脂质由于被锁定在蛋白质-脂质复合物基质中（主要在膜中）而仍然存在于福尔马林固定的组织中。这些脂质信号随后可通过光谱病理学检测到，并且仍可能被证明具有诊断用途。
Formalin-fixed paraffin-embedded (FFPE) tissue sections are routinely analysed for biochemical discrimination by vibrational spectroscopy techniques in the spectral pathology community. In these experiments, it is usually desirable to remove the paraffin from the tissue. This is most commonly performed by the use of xylene but other solvents such as hexane are also used. It is thought that the removal of unbound paraffin wax by such solvents also leaches out lipids native to the tissue, leading to the perception by some that any subsequent analysis on remaining lipids of dewaxed tissue may be unreliable. The scope of the study was to make an assessment of whether a dewaxing protocol can demonstrate that paraffin wax is reliably removed in relation to the detectable limits of transmission mode infrared spectroscopy. In this study, a specific sampling region of two serial FFPE sections of human prostate cancer were analysed by monitoring the methylene hydrocarbon-associated vibrations as a function of solvent immersion time during washes of either hexane or xylene. Results of the study indicate that after 5-10 minutes of immersion in the solvent the hydrocarbon-associated vibrations remain fairly consistent across the tissue. This suggests that while methylene chains of free, unbound tissue lipids are leached from the tissue (assumingly in the first tissue processing stages prior to paraffin embedding) solvent-resistant lipids remain present in formalin-fixed tissue due to being locked into protein-lipid complex matrices, predominantly in the membranes. It is these lipids signals that are subsequently detectable by spectral pathology and may still prove to be of diagnostic use.