# DNA testing

**URL:** <https://boards.straightdope.com/t/dna-testing/532131>\
**Category:** Factual Questions\
**Created:** [March 11, 2010, 5:35pm UTC](https://boards.straightdope.com/t/dna-testing/532131 "2010-03-11T17:35:03Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![bizerta](https://avatars.discourse-cdn.com/v4/letter/b/3be4f8/32.png) [@bizerta](https://boards.straightdope.com/u/bizerta)\
**Post date:** [March 11, 2010, 5:35pm UTC](https://boards.straightdope.com/t/dna-testing/532131/1 "2010-03-11T17:35:03Z")

</div>

Some questions about DNA testing.

If one took two donors’ samples of blood and throroughly mixed them togehter, would a lab be able to tell that fact and get a DNA profile of each donor?

I’ve heard of DNA being used to determine paternity. Can it go back any further? If I had a DNA sample of a person thought to be my great-grandfather, would a lab be able to determine whether he was, in fact, a blood ancestor?

If (George Orwell: eat your heart out) everyone’s DNA were on file in a database, and if I had no idea who my natural parents were, would a DNA test be able to determine who they were?