Illustration of methods for SBF-SEM, FIB-SEM and Tom-TEM. A: Illustration of the imaging procedure for SBF-SEM and FIB-SEM. The scanning electron beam (centre) raster scans a specific area of the surface and backscattered (or secondary electron) micrographs are collected. For SFB-SEM (left) the sample is raised and then cut with a diamond knife, for FIB-SEM (right) a focused ion beam mills a layer from the surface before returning to the scanning mode. B: Secondary Electron and C: Backscattered Electron Micrographs from SFB-SEM. P = Podocyte, GBM = Glomerular basement membrane and C = Capillary Lumen. * Knife mark is less visible in C than B. Scale Bars = 1 μm D: Electron tomography (Tom-TEM) The electron beam passes through the sample. The sample is tilted so that images are taken at different angles without moving the detector (camera). The images at known viewing angles can then be reconstructed, for example using weighted back-projection, to produce a 3D image of the sample.