The 'Iceman': molecular structure of 5200-year-old skin characterised by Raman spectroscopy and electron microscopy

The molecular state of about 5200-year-old skin from the so-called 'Iceman' (Similaun man or Otzi) has been characterised using Fourier transform Raman spectroscopy, and has been compared with that of contemporary man. Contemporary skin was also freeze-dried (to mimic the conditions under which the ancient skin was preserved) and its molecular structure was compared with that of Iceman skin. The results showed that the proteinaceous moiety of the ancient skin had degraded considerably and, although olefinic bonds had probably oxidised, the lipoidal component was largely unaltered. Electron microscopical comparisons of Iceman and contemporary skin showed that the gross structure of Iceman skin had survived essentially intact for five millennia.