Scientists unlock blood mystery in mummy
Vampires and werewolves can step aside because a real life mummy has just taken the spotlight. Scientists recently discovered the oldest blood known to modern science inside a mummy. Ötzi is a 5 000-year-old glacier mummy, discovered accidently by a pair of tourists in the Ötztal Alps on the Austrian-Italian border in 1991. While scientists got a rare glimpse into the life of Ötzi around the time he was alive, many years Before the Common Era (BCE), researchers failed to identify any traces of blood... until now.
Scientists have pored over almost every single detail of Ötzi since the mummy was discovered more than 20 years ago. They have examined his clothes, finding them to be very sophisticated, his tools and even his genetics as scientists successfully decoded his deoxyribonucleic acid (DNA). Samples taken from his stomach and intestines have even allowed scientists to reconstruct his very last meal. Examinations of his aorta had failed to yield results.
Enter a team of scientists in Germany and Italy that harnessed the latest advances in nanotechnology and succeeded in locating red blood cells in Ötzi’s wounds, thereby discovering the oldest traces of blood to have been found anywhere in the world.
'Up to now there had been uncertainty about how long blood could survive — let alone what human blood cells from the Chalcolithic period, the Copper Stone Age, might look like,' said Albert Zink, head of the Institute for Mummies and the Iceman at the European Academy, Bozen-Bolzano (EURAC) in Italy. He went on to explain the starting point for the investigations which he undertook with Marek Janko and Robert Stark, materials scientists at the Center of Smart Interfaces at Darmstadt Technical University in Germany.
Early examinations of the body had discovered an entry wound in Ötzi's back from an arrow. The scientists used an atomic force microscope to investigate thin tissue sections from this wound as well as from a laceration on his right hand.
While examining the arrow wound, the team also identified fibrin, a protein involved in the clotting of blood. 'Because fibrin is present in fresh wounds and then degrades, the theory that Ötzi died straight after he had been injured by the arrow, as had once been mooted, and not some days after, can no longer be upheld,' explained Dr Zink.
Modern forensic medicine has been unable to determine how long a trace of blood had been present at a crime scene. However, scientists Zink, Janko and Stark are convinced that the nanotechnological methods they tested on Ötzi's blood to analyse the microstructure of blood cells and minute blood clots might possibly lead to a breakthrough in this area.
'To be absolutely sure that we were not dealing with pollen, bacteria or even a negative imprint of a blood cell, but indeed with actual blood cells, we used a second analytical method, the so-called Raman spectroscopy method,' said Drs Janko and Stark, who, with Dr Zink, are also members of the Center for NanoSciences in Munich.
In Raman spectroscopy, the tissue sample is illuminated by a laser beam and analysis of the spectrum of the scattered light allows one to identify various molecules. According to the scientists, the images derived from this process corresponded to present-day samples of human blood.
The team published the results of this research in the Journal of the Royal Society Interface.
European Academy of Bozen/Bolzano
Journal of the Royal Society Interface
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