Human dermis from different ex vivo sources. Two-photon-excited SHG (collagen, green) and autofluorescence (red) of 3D dermis from native back skin (A), abdomen (B), and cadaveric skin of unspecified body region (C) (AlloDerm). (A) Skin left-over from the tumor margin not needed for histopathological diagnosis was used as non-fixed whole-mount few hours post-surgery. (B) DED was obtained from abdominal skin corrections, cultivation for 2 weeks61 and fixation by paraformaldehyde. (C) AlloDerm was used as provided by the supplier (LifeCell Corporation, Branchburg, NJ, USA) 37. All samples were monitored from the open margin of the dermal side. Image processing was performed as described in Fig. 2. White arrowheads, collagen bundles; empty arrowheads, elastic fibres. Bars, 100 μm.