The bloodstains on the Shroud are from real blood.
Alan Adler, an expert on porphyrins, the types of colored compounds seen in blood, chlorophyll, and many other natural products concluded that the blood is real. In collaboration with John Heller, the conclusions that the blood is real was published in the peer-reviewed scientific journal Applied Optics [19, (16) 1980]. The heme was converted into its parent porphyrin, and this was confirmed with spectral analysis.
Baima Bollone also found both the heme porphyrin ring of blood and the globulin in flakes of blood from Shroud samples, independently confirming the work of Adler and Heller.
In addition, x-ray-fluorescence spectra showed excess iron in blood areas, as expected for blood. Microchemical tests for proteins were positive in blood areas but not in any other parts of the Shroud.
Some skeptics have argued that the blood could not be real because old blood turns black and the bloodstains on the Shroud are red. This argument is scientifically invalid and the reason the bloodstains are red are simple:
1) Ancient cloth, as it was manufactured in the Middle East during the first century, was starched on the loom and then washed in suds of the Soapwort plant. Ingredients of this natural soap are hemolytic, which would keep the blood red.
2)The blood on the Shroud is rich in bilirubin, a bile pigment produced when a human body is under severe traumatic stress. Bilirubin is bright red and stays red and will cause old blood to remain red in color.
From forensic observation we see that the stains are from real human bleeding from real wounds on a real human body that came into direct contact with the cloth. When the stains formed, the man was lying on his back with his feet near one end of the fourteen foot long, banner shaped piece of cloth.
The cloth was drawn over the top of his head and loosely draped over his face and the full length of his body down to his feet. Many of the stains have the distinctive forensic signature of clotting with red corpuscles about the edge of the clot and a clear yellowish halo of serum.
Some forensic experts think that can identify that some of the blood flow was venous and some was arterial. Most of the blood flowed while the man was alive and it remained on his body. There is some blood that clearly oozed from a dead body, as was the case for stains resulting from a wound in the mans chest. Here, the blood, with a deeper color and more viscous consistency, as is the case for blood from a postmortem wound, ran from a chest wound, flowed around the side of the body and formed a puddle about the mans lower back.
Mingled with the blood from the chest wound are stains from a clear bodily fluid, perhaps pericardial fluid or fluid from the pleural sac or pleural cavity. This suggests that the man received a postmortem stabbing wound in the vicinity of the heart.
