H 600iv transmission electron microscope

Fresh brain tissues were taken from the left cortex, cut into about 1-mm³ (link) cubes, and fixed in 2.5% glutaraldehyde for 24 h. The samples were fixed in 1% osmium tetroxide for 2 h, dehydrated in graded acetone, and embedded in araldite. Sections were cut at 50 nm and stained with uranyl acetate and lead citrate. The ultrastructures of the BBB were observed under an H-600IV transmission electron microscope (Hitachi, Tokyo, Japan).

HepG2 cells were incubated with dimethylsulfoxide for 24 hours, and fixed with 2.5% glutaraldehyde for 12 hours, and later with 1% osmium tetroxide at 4°C for 2 hours. After rapid staining with uranium acetate, the cells were dehydrated, and the liquid was renewed thrice. The cells were embedded and sliced before double staining with uranium acetate and lead citrate, followed by observation of the ultrastructural changes under an H‐600IV transmission electron microscope (Hitachi, Tokyo, Japan).

Scanning electron microscopy was performed according to a modified method using an Apreo S scanning electron microscope (Thermo Fisher, Waltham, Massachusetts, United States) (Kang et al., 2006 ). For SG detection in the internode, paraffin sections were made as described by Li et al. (2009a (link),2009b (link)). The paraffin sections were stained with I₂‐KI and observed under a light microscope (Nikon DS‐U3; Nikon, Minato City, Tokyo, Japan) (Peng et al., 2014 (link)). For transmission electron microscopy analysis, leaves were treated in 3% glutaraldehyde and then fixed in 1% osmium tetroxide. After dehydrating in a gradient acetone series, the leaf sections were embedded in Epon812 medium for thin sectioning. Uranyl acetate and Reynolds' lead citrate were used to stain the thin sectioning, and an H‐600 IV transmission electron microscope was used to assess the picture (Hitachi, Chiyoda City, Tokyo, Japan) (Li et al., 2015 (link)).