[Uriah_lost]

I just finished a series of books based on this idea. Pretty entertaining reading up until the last bit. I'll try and find the title and author and post it later.

[BlackVeil]

I think you might mean The Genesis Code, by John Case. An entertaining thriller about an attempt to clone the blood of Christ, as preserved in relics.

[Uriah_lost]

Found it:

In His Image (The Christ Clone Trilogy, Book 1)
by James BeauSeigneur
http://www.amazon.com/gp/product/0446531251/qid=1141796506/sr=2-1/ref=pd_bbs_b_2_1/103-7332459-5899007?s=books&v=glance&n=283155

Can't really recommend it but YMMV. The premise that they harvest some viable DNA from the shroud of Turin is the start of many "suspension of disbelief" moments in the story.