Red blooded Ötzi

Raman spectroscopy has revealed that red blood cells preserved in the Iceman still contain oxygen-transporting porphyrin molecules.

Ötzi the Iceman was an important member of his ancient Tyrolean tribe. He planned to return to his village, but he took an arrow to the… shoulder… and instead was mummified in a glacier until discovery in 1991. His body has been so well preserved over the last 5300 years that the collagen in his skin is still intact. Ötzi is still contributing to science, and a recent study from Marek Janko and colleagues analysed the blood in Ötzi’s veins (Janko et al. 2012).

Small tissue samples were taken from wounds on Ötzi’s right hand and left shoulder. The Ötzi samples and fresh human tissues (from a volunteer) were prepared so that the red blood cells could be studied. Three analytical techniques were applied to the tissues, including Raman spectroscopy. Raman spectra from the ancient tissues were very similar to the spectrum of modern human blood. The peaks in each Raman spectrum were characteristic of a porphyrin – heme – which proved two things. First, there is still blood frozen in Ötzi’s arteries and veins. Second, the molecule heme, which has the important role of transporting oxygen around a living body, can be preserved for 5300 years. The heme in Ötzi’s tissues has degraded slightly, but it is still the red blood pigment we are all familiar with.

Janko M, Stark RW, Zink A. 2012. Preservation of 5300 year old red blood cells in the Iceman. Journal of the Royal Society Interface.doi:10.1098/rsif.2012.0174

Images compiled from Wikimedia Commons ( here, here and here)