Scanning electron microscopy of adventitial ECM hydrogel. Decellularized tissue and ECM hydrogels were fixed in 2.5% glutaraldehyde and processed for scanning electron microscopy. Representative micrographs showing decellularized human adventitia (Adv) (A-B), human Adv hydrogel (C-D), porcine Adv hydrogel (E-F) and porcine small intestinal submucosa (SIS) hydrogel (G-H) at 5,000X (A, C, E) and 10,000X (B, D, F) magnifications. All scale bars=1μm.