Figure 2. Electron Microscopy.

(A) TEM images of an airway organoid cross-section exhibiting the polarized epithelium comprised of basal, secretory, brush, and multi-ciliated cells, followed by detailed visualizations of apical microvilli and cilia with their characteristic microtubule structures. Scale bars, 10 μm (left), 2 μm (right top), and 500 nm (right bottom). (B) SEM images of a partially opened airway organoid showing its 3D architecture, followed by detailed visualization of apical surfaces of secretory and multi-ciliated cells. Scale bars, 50 μm (left) and 2 μm (right). Reproduced under the terms of the Creative Commons Attribution 4.0 International License [155].