Radiocarbon dating bone collagen
But even if there were blood on the shroud, that would have no bearing on the age of the shroud or on its authenticity.
Skeptics believe that the shroud of Turin is just another religious relic invented to beef up the pilgrimage business or impress infidels.
For example, it is claimed to be the negative image of a crucifixion victim.
It is claimed to be the image of a man brutally beaten in a way which corresponds to the way Jesus is thought to have been treated.
It is claimed that there is type AB blood on the shroud. Blood has not been identified on the shroud directly, but it has been identified on sticky tape that was used to lift fibrils from the shroud. Other tests by Adler and Heller have identified it as blood.* If it is blood, it could be the blood of some 14th century person.
It could be the blood of someone wrapped in the shroud, or the blood of the creator of the shroud, or of anyone who has ever handled the shroud, or of anyone who handled the sticky tape.Some have noted that the head is 5% too large for its body, the nose is disproportionate, and the arms are too long. In any case, the image is believed by many to be a negative image of the crucified Jesus and the shroud is believed to be his burial shroud. Apparently, the first historical mention of the shroud as the "shroud of Turin" is in the late 16th century when it was brought to the cathedral in that city, though it was allegedly discovered in Turkey during one of the so-called "Holy" Crusades in the so-called "Middle" Ages.