This so-called "DNA testing" is little better than throwing chicken entrails and probably less effective than floating witches. On a scale of genuine science, it's on a par with lie detection, and despite the highly-publicised cases, it's not something that most reputable forensic scientists would use if they could get the number of a reliable psychic.
I hope people realize that this is just plain wrong. And this posting is full of incorrect information and pseudoscience. A human genome is 3 billion bases long. More importantly, every single cell in your body has all 3 billion of them (okay, red blood cells don't have any DNA in them, but that's an exception). Any tissue sample will contain many identical copies of all 3 billion of them, junk and genes alike. The poster doesn't realize that the junk is in fact the most informative part when comparing individuals.
That's enough criticism for one post.
The only thing cheaper than hardware is talk.