Embedment-free section electron microscopy.
Embedment-free section electron microscopy.
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免包埋切片电子显微镜。
DOI：
10.1093/jmicro/dfl030
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
H. Kondo
中科院分区：
文献类型：
--
作者：
H. Kondo
由于电子密度与环氧树脂相似或低于环氧树脂的生物实体的环氧切片可能妨碍清晰观察，作者强调了无包埋切片电子显微镜对于重新检查和/或澄清生物样品结构是必要的，无包埋电子显微术是通过使用水溶性聚乙二醇（PEG）作为瞬时包埋介质和通过临界点-通过将半薄切片浸入水中去除PEG包埋后干燥无包埋切片。通过无包埋电子显微镜，作者提出了五个主要发现：在各种细胞中和在给定细胞的细胞内区域中出现具有不同致密性的微梁晶格，在体外从相应增加浓度的人工蛋白质溶液中忠实地再现具有增加的致密性的微梁样链晶格，在体外，在给定浓度下，来自凝胶化明胶的晶格比来自分离明胶的晶格更致密，通过细胞的高渗或低渗冲击处理，微小梁晶格的致密性的可变性，以及在离心的神经节细胞的向心半月形中细胞内蛋白质的受限外观，其被实质上致密的微小梁晶格占据。从这些发现中，得出了几个结论：微梁的单个链本身是没有意义的，微梁的出现代表了一定浓度的蛋白质的存在，因此，水性细胞质很可能相当于水溶液。此外，在给定细胞中表现出不同致密性的两个连续晶格结构域的出现可能代表细胞质结构域的溶胶至凝胶状态的连续性的发生。因此，提出细胞内细胞器的定位和运动不仅受细胞骨架的控制，而且还受细胞内蛋白质的浓度和溶胶/凝胶状态的控制。此外，一些潜在的实用性的包埋自由电子显微镜也已被证明。
Because of potential hindrance of clear viewing in epoxy sections of biological entities having an electron density similar to and lower than that of epoxy resin, the author has stressed that the embedment-free section electron microscopy is necessary for re-examination and/or clarification of biological specimen structures, and that the embedment-free electron microscopy is reliably done by using water-soluble polyethylene glycol (PEG) as a transient embedding media and by critical point-drying of embedment-free sections after de-embedment of PEG by immersion of semithin sections into water. With the embedment-free electron microscopy, the author has presented five major findings: the appearance of microtrabecular lattices with different compactnesses in various cells and in intracellular domains of a given cell, the faithful reproduction of microtrabecula-like strand lattices in vitro with increasing compactnesses from artificial protein solutions at correspondingly increasing concentrations, the appearance of more compact lattices from gelated gelatin than from solated gelatin at a given concentration in vitro, the changeability in compactnesses of the microtrabecular lattices by hyper- or hypotonic shock treatments of cells, and the confined appearance of an intracellular protein in the centripetal demilune of centrifuged ganglion cells which is occupied with the microtrabecular lattices of a substantial compactness. From these findings, several conclusions are drawn: individual strands themselves of the microtrabeculae are meaningless, the appearance of microtrabeculae represents the presence of proteins at a certain concentration, and it is therefore likely that the aqueous cytoplasm is equivalent to the aqueous solution. In addition, it is possible that the appearance of two contiguous lattice domains exhibiting different compactnesses in a given cell may represent the occurrence of a contiguity of sol to gel states of cytoplasmic domains. It is thus proposed that the localization and movement of intracellular organelles are controlled not only by the cytoskeletons but also by the concentration and sol/gel states of intracellular proteins. In addition, several potential usefulness of the embedment-free electron microscopy has also been demonstrated.