S2150

Eight weeks post transplantation, we estimated the survival rate of hUC-MSCs transplanted into the injured spinal cords. Paraffin sections were dewaxed and rehydrated, and then repaired with antigen. After being blocked, the sections were exposed to primary antibody against human nuclear (HuNu; 1:500, ab216943, Abcam, UK) at 4°C overnight, followed by reaction with secondary antibody goat anti-mouse IgG H&L (Alexa Fluor® 594, ab150120, Abcam, UK). Next, the nuclei were counterstained with DAPI Staining Solution (ab228549, Abcam, UK). The model group functioned as the negative control group. After the sections were mounted with the glycerol jelly mounting medium (S2150, Solarbio, China), the immunofluorescent images were acquired using a fluorescence microscope (BX53, OLYMPUS, Japan).

H&E staining was performed as previously described (Guo et al., 2016 (link)). In brief, after deparaffinization and rehydration, 5-μm sections were stained with hematoxylin solution (G1120, Solarbio, Beijing, China) for 5 min at room temperature and washed twice with tap water (2 min/wash). The slides were then stained with eosin solution (G1120, Solarbio, Beijing, China) for 3 min at room temperature and washed twice with tap water (2 min/wash). Next, the slides were dehydrated in increasing concentrations of alcohol (75%, 85%, 95%, and 100% alcohol) for 2–3 s and rinsed in 100% alcohol for 1 min. The slides were then made transparent using xylene, sealed with glycerol gelatin aqueous slide mounting medium (S2150, Solarbio, Beijing, China), and mounted and photographed using an Olympus microscope (Olympus Corporation, Tokyo, Japan).