Gels was delicately scoop in their native concentration and release in the fixative (1.6% formaldehyde #15714, 2.5% glutaraldehyde #16220 in 0.1M cacodylate buffer #12300, all from ESM, Hatfield, PA) for 16h at 4C. They were rinsed 3x for 5 min in cacodylate buffer and dehydrated through an ethanol series (30%, 50%, 70%, 90%, 95%, 100%) 10 min each and wash 2x in ethanol 100% for 20 min. Dislocated pellets can be recover with centrifugation at 300g. Pellets were post-dehydrated with HMDS (#16700, EMS) 2x 20 min and let to dry overnight under a fume hood. The next day, the pellets are mounted on an aluminium stub (#75260, EMS) using aluminium backed carbon tabs (#77828-08, EMS) and gold sputtered with a EMS 950x/350s sputter coater and observed with a JEOL 6360LV scanning electron microscope.