Meet Otzi – the 45-year-old prehistoric man who was killed by an arrow some five millennia ago. Ever since mountain climbers found him sticking out of a glacier in the Austrian Alps back in 1991, scientists have been studying him, taking samples from all over his somewhat-preserved body.

According to the Center for Smart Interfaces at Darmstadt Technical University in Germany, scientists have already sequenced his DNA and determined his last meal via intestinal samples. Now, they are announcing another huge breakthrough – the discovery of red blood cells at wound sites on Otzi’s body.

The cells came from an arrow wound as well as a laceration on Otzi’s hand. This 5300-year-old blood would be a scientific first – the oldest samples of human blood ever analyzed.

“They really looked similar to modern-day blood samples,” Albert Zink told Reuters. Zink is the head of the Institute for Mummies and the Iceman at the European Academy in Bolzano, Italy. “So far, this is the clearest evidence of the oldest blood cells,” he said.

The way in which the scientists analyzed the prehistoric blood is the real breakthrough that could influence modern forensic science.

After the samples were taken from the arrow wound and hand, here’s how the process worked –

Shape and size of the blood cells have been verified by an atomic force microscope. This nanotechnological equipment scans the surface of the tissue samples with a small tip. The deflections of the tip are measured with sensors and a 3-dimensional digital copy of the surface is created. As a result images of the typical donut shaped red blood cells were produced, just like they still look like these days.

To exclude other options like pollen or bacteria, a second method has been applied. Raman spectroscopy has been used to illuminate the tissue samples with a laser beam in order to identify the characteristic Raman spectra of haemoglobin.

The above image is an actual 3D scan of one of Otzi’s red blood cells. How amazing that blood from 5300 years ago could be preserved so well and so closely resemble the blood cells of you and me.