Fig. 1

Comparison of TEM and SEM imaging. a TEM imaging. b SEM imaging. Both images were taken from thin sections of a block with osmium tetroxide, excess thiocarbohydrazide (TCH), and osmium tetroxide staining (OTO). For TEM imaging, the region of interest (100 * 800 μm) was trimmed, sectioned, and loaded onto a TEM grid. Unlike TEM, SEM imaging was selected from a large area (276.3 * 414.4 μm) in SEM without trimming before sectioning