Studying skin of an Egyptian mummy by infrared microscopy

The state of conservation/degradation of mummy human remains, can be inferred from their biochemical composition, as well as the secondary structures of proteins. Infrared microscopy is a very appropriate technique for addressing such issues. In this study, skin leg of an Egyptian mummy, was collected and prepared by microtomy, and was analysed using an infrared imager (Spectrum™ Spotlight) and using synchrotron infrared microscopy. Complementary analyses at both large scale and size close to the diffraction limit help tremendously for understanding the state of degradation. The external layer of mummy skin appears to be more preserved as evidenced by the presence of characteristic biological vibrational features (in particular amide bands) in spectra collected within this region. Adipocere and calcium oxalate are the main degradation products identified in the mummy skin. The origin of the degradation process is not yet fully understood.