Liu Zhiang, Xue Haowen, Chen Qi, Yang Ge
TEM Laboratory Experimental Teaching and Equipment Management Center, Qufu Normal University, Qufu, Shandong, People's Republic of China.
College of Life Sciences, Qufu Normal University, Qufu, Shandong, People's Republic of China.
J Microsc. 2023 Dec;292(3):117-122. doi: 10.1111/jmi.13235. Epub 2023 Oct 19.
Exosomes can not only be used as markers of tumour metastasis but also be used for noninvasive diagnosis of clinical diseases, which holds significant medical research value. Observing the morphology and distribution of exosomes using transmission electron microscopy (TEM) is highly significant. In this study, we use breast tumour cell (MDA-MB-231) exosomes as a representative sample and focus on the extraction and purification of exosomes, as well as the investigation of optimal conditions for the observation of exosomes using TEM. Through comparative tests, we obtained the optimal dilution concentration and staining method for TEM of exosomes, the best dilution concentration is 100 times, the best negative staining time is 1.5 min. Western blotting and scanning electron microscopy (SEM) confirmed the presence of exosome. The particle size experiment shows that the size of exosomes is mainly distributed between 60 nm and 150 nm. This method provides a reference for TEM sample preparation of subcellular structures and small molecular biomaterials other than exosomes.
外泌体不仅可作为肿瘤转移的标志物，还可用于临床疾病的无创诊断，具有重要的医学研究价值。利用透射电子显微镜（TEM）观察外泌体的形态和分布具有重要意义。在本研究中，我们以乳腺肿瘤细胞（MDA-MB-231）外泌体作为代表性样本，重点研究外泌体的提取和纯化，以及利用TEM观察外泌体的最佳条件。通过对比试验，我们获得了外泌体TEM的最佳稀释浓度和染色方法，最佳稀释浓度为100倍，最佳负染时间为1.5分钟。蛋白质免疫印迹法和扫描电子显微镜（SEM）证实了外泌体的存在。粒径实验表明，外泌体的大小主要分布在60nm至150nm之间。该方法为除外泌体之外的亚细胞结构和小分子生物材料的TEM样品制备提供了参考。
