In 1995, threads that had been taken from the shroud during the 1978 STURP investigations were examined at Genoa's Institute of Legal Medicine. The chief scientist reported finding DNA and that "the DNA chain is very long, and we are able to identify very small sectors representing individual characteristics which can ultimately enable us to identify the individual from whom they derive."'

Dr. Victor Tyron and his wife, Nancy Mitchell Tyron of Texas University's Center for Advanced DNA Technologies, performed an independent test for DNA and established that the threads contained human blood.

The State University of New York could not confirm any DNA claims because the blood appears to be so old that the DNA is badly fragmented and concluded that proper analysis is doubtful.

A characteristic of the cloth — blood stains — is perhaps the more religiously significant portion of the image and of the debate.

Christians believe Jesus bled and died as a sacrifice for mankind's sins. That offering is remembered during religious services today in most faiths. In many, wine or liquid taken during sacrament services is blessed and taken as a representation of Christ's blood or is said to literally become Christ's blood when followers drink it.

Despite tests demonstrating that blood does exist on the shroud, a debate has emerged regarding the color of stains. Many believed that since exposed blood eventually turns a brownish color, then the stains on the shroud could not be blood because of their deep, red appearance and were more likely paint.

But STURP members offered the biological explanation that if the man of the shroud had undergone torture, scourging, crucifixion and shock, then in less than 30 seconds, a high amount of yellowish-orange bilirubin would have been produced.