Can you buy a DNA test to find out your heritage?

Question:...or do you go somewhere to do this?

Best Answer - Chosen by Asker: ...or do you go somewhere to do this?

I used www.familytreedna.com. They sent a kit, I swabbed the insides of my cheeks, returned the kit, in about 3 weeks they sent a written report, plus access to a website, listing recent genealogical sources, etc.
The price depends upon how extensive you want to research.
Male DNA mutates at a much faster rate than female DNA; due to these facts, they CAN determine just what countries (modern countries) your ancestors came from.

my niece just bought a dna test kit from Canada it was a $100.00 and needed to be sent back to Canada for reading She found it on the internet. If you use the usa expect to pay about 1 grand

You can definitely do this. As it happens, there's been a banner ad on Rootsweb's site the last few days advertising it! I'm attaching the link below. The tests cost from $149 to $199, depending on which one is right for you.

Here are some interesting statements from deep in the guts of some of these services...these are unmodified direct cut and pastes except I added the quotes...

"The margins of error are very large and thus even an identical match could providing a median figure of 4 generations could actually be somewhere between 0 and 14 generations - thus not very accurate. It is always best to overlay the genetic data over paper doucumentation."

"Although it may indicate affinity with and higher frequency within a particular population e.g. Jewish, Native American etc., the results are not usually exclusive to one population. For example, Middle Eastern Jews and Arabs share the same haplogroups."

Of course each individual needs to determine the best way to waste their own money (I have my favorite ways to waste mine)....so before you do, go deep into the fine print of these services and find out all the ways they inform you that their results probably don't mean squat - or how they consider 60% to be very accurate.