Qusestion about DNA testing

Rating: Null/10 (30 May 2006)

The main battle in this movie between the Catholic Church and the Priory of Scion in this movie seems to me that if a modern day descendant of Mary Magdeline could be DNA tested and proved to be a direct link to Mary M. then that would prove that this person is the long lost offspring of Jesus. My question is, to prove this wouldn't they also need a strand of Jesus's DNA to show that Jesus and Mary Magdeline had produced a blood line. So without Jesus's DNA it seems to me that the only thing that could be proved is a link to Mary M.
Oh and please do not turn this thread into a religious debate, if hell exists I will not be going there because I have seen this movie (but I might be for something else) , seeing a movie will not change anything I believe in (I did not start believing in UFO's when I watched "Close Encounters" and I did not quit believing in the stories my dad told me after I watched "Big Fish" OK...Flak vest on, Helmet strapped to my head...FIRE AWAY