Abstract：
Retinal organoids (ROs) are a three-dimensional culture system mimicking human retinal features that have differentiated from induced pluripotent stem cells (iPSCs) under specific conditions. Synapse development and maturation in ROs have been studied immunocytochemically and functionally. However, the direct evidence of the synaptic contact ultrastructure is limited, containing both special ribbon synapses and conventional chemical synapses. Transmission electron microscopy (TEM) is characterized by high resolution and a respectable history elucidating retinal development and synapse maturation in humans and various species. It is a powerful tool to explore synaptic structure in ROs and is widely used in the research field of ROs. Therefore, to better explore the structure of RO synaptic contacts at the nanoscale and obtain high-quality microscopic evidence, we developed a simple and repeatable method of RO TEM sample preparation. This paper describes the protocol, reagents used, and detailed steps, including RO fixation preparation, post fixation, embedding, and visualization.
摘要：
视网膜类器官(RO)是模拟在特定条件下从诱导多能干细胞(iPSC)分化的人视网膜特征的三维培养系统。已在免疫细胞化学和功能上研究了RO中的突触发育和成熟。然而,突触接触超微结构的直接证据是有限的，包含特殊带状突触和常规化学突触。透射电子显微镜（TEM）的特点是高分辨率和可敬的历史，阐明了人类和各种物种的视网膜发育和突触成熟。它是探索ROs中突触结构的有力工具,广泛应用于ROs的研究领域。因此,为了更好地在纳米尺度上探索RO突触接触的结构，并获得高质量的微观证据，我们开发了一种简单，可重复的ROTEM样品制备方法。本文介绍了该协议，使用的试剂，和详细的步骤，包括RO固定准备，固定后，嵌入,和可视化。
