Every day people contact me for DNA advice. This page is designed to be a one-stop resource for answering the most common questions.
I am also including links to valuable resources that can help you learn more about genetic genealogy, do more with your results, and get personal assistance where needed.
There are five companies whose tests I use and recommend:
All are reputable companies with good tests and huge databases. Each one has been extremely valuable to me and my extended family. Plus, each company’s web site is an important educational resource. Click the above links to learn more directly from each company and see current pricing on their tests
There are three major test types: autosomal DNA, Y-DNA, and mitochondrial DNA.
Autosomal DNA testing is the most versatile test type and with most of the tests now priced below $100, it's the most economical.
This looks at the DNA passed down from all your ancestors on both sides of your family. You can uncover previously unknown relatives, measure how closely two people are related, e.g. distinguishing between full and half siblings, and see an estimate of your overall ethnic ancestry.
To find unknown relatives I recommend: Family Finder by Family Tree DNA, AncestryDNA, 23andMe and MyHeritage DNA. Each test has unique strengths. Since the databases are separate and mostly comprised of different people, my DNA advice to adoptees and anyone wishing to find as many DNA relatives as possible is to get into every possible database.
At the time of this writing, Living DNA does not provide a list of other testers that you match. Instead, it focuses on breaking down British ancestry into subregions. That's something that no other test does.
Y-DNA testing examines a man’s Y chromosome. It is used to trace the direct paternal line, i.e. your father’s father’s father etc. back hundreds of years or more. Since surnames usually pass down the same way, it can often uncover the last names of unknown fathers for male adoptees and other men.
The test will also identify your paternal haplogroup. That will reveal the migration path your ancestors followed thousands of years ago.
Family Tree DNA has the largest Y-DNA database by far and allows you to join any of more than 8,000 individual projects. These projects focus on surnames, geographic locations, or haplogroups. FTDNA offers Y-DNA tests of 12, 37, 67, or 111 markers. My DNA advice is to test 37 or 67 markers.
Mitochondrial DNA testing is available to all. Your mtDNA came from your mother, who got it from her mother and so on. Using this test to trace the maternal line is often more difficult than using Y-DNA testing to trace the paternal line. That’s because the surnames typically change at every generation down the female line.
Furthermore, your matches may share common ancestors that lived hundreds or even thousands of years ago. That makes the mtDNA test my least favorite test when you're just fishing for relatives.
My DNA advice regarding mtDNA testing is to leave it for testing a specific assumption that two people are related through the same maternal line ancestors. The test will also provide your maternal haplogroup.
Family Tree DNA is the obvious provider of choice. Their Full Mitochondrial Sequence test is the only test to check 100% of your mitochondria.
The process is basically the same for all the recommended tests. You go to the company’s web site and order a test with a credit or debit card. They ship a home test kit to the address you provide.
Depending on the company, you will collect your sample either by lightly scraping inside your cheeks with a swab or by spitting saliva into a tube. No blood is required.
Following directions, you mail the sample back to the lab. It usually takes a few weeks to get results. Once your testing is complete, you will be notified by email.
Using your unique user name or kit number and a password, you log into your personal account at the company’s web site to see your results.
Just this year, two of the autosomal DNA databases began to accept free transfers from others. With that in mind, here is the new, cost-effective strategy for adoptees and anyone else wanting to get into every database:
1. Start with the AncestryDNA test. It has the largest database and the most family trees linked to testers. To take full advantage of the most powerful matching features, you may need to purchase an optional subscription to Ancestry..
2. Transfer your raw Ancestry DNA data into the Family Finder test at Family Tree DNA, and the MyHeritage DNA test. Your closest relatives may have done a different test and you want to exhaust every possibility of finding them.
3. Order the 23andMe test to get into the last important database. The less expensive Ancestry option is sufficient. The more expensive Health + Ancestry option also provides some genetic health information approved by the FDA in the U.S. and by other regulatory bodies elsewhere.
The following web sites can help you get the most information from your autosomal DNA results. For some, I have a web page on my site that describes the resource in more detail. For others, I link directly to the site.
GEDmatch.com lets you upload your raw autosomal DNA data and your GEDCOM genealogy files for comparison with others. If you have only done one or two of the autosomal tests, this may uncover some additional matches from people who tested with a different company AND took the added step of uploading to GEDmatch.
The site includes many powerful tools to help you build and expand your family tree. My DNA Advice? Definitely use this site.
DNAAdoption.com was created to help adoptees discover their birth families through triangulation of their DNA match results. Yet the methodology and tools on the site can be used by anyone with autosomal DNA data.
DNAGedcom.com provides additional tools that enhance the process of working with your DNA match results.
DNA Land is an academic project that provides some interesting features for those who choose to upload their autosomal data.
Besides the many pages on this DNA Testing Adviser web site, my best DNA advice is to check the following resources:
International Society of Genetic Genealogy. There are no dues or fees to join this excellent organization. Their web site includes an outstanding Wiki where you can look up information on many DNA testing topics.
DNA Books. See my page for recommended books you can buy or request from your local library.
Yahoo Groups. There are some good discussion groups on Yahoo that use the mailing list format for discussion. Unless you want to be buried in individual emails, my DNA advice is to choose the Daily Digest option where you get about one email a day from each group.
DNA-NEWBIE is the group managed by ISOGG. It’s an excellent place to ask questions and learn.
DNAAdoption is the group managed by DNAAdoption.com. It is primarily focused on the use of DNA testing by adoptees searching for birth families. Yet anyone seeking lost family or an unknown father, for example, can benefit from the discussions.
Facebook Groups. With so many people on Facebook, many groups have formed to help those seeking answers through DNA testing. Most are closed groups and you must request admission to join.
Genetic Genealogy Tips & Techniques, stared by Blaine Bettinger, is one of my favorite places for DNA discussions.
The ISSOG Group is open to ISOGG members and has many lively discussions about various aspects of DNA testing.
DNA Detectives is where adoptees and DNA-savvy search angels come together to share search tips, answer questions, and celebrate reunions brought on by DNA testing.
Many people ask me about paternity testing. There are many labs that offer the standard DNA paternity test, typically based on 16 markers. When you are testing a parent and a child, such testing can provide solid Yes or No answers because the child has two values at each marker and one must come from each parent.
If you need a legal test where the results can be used in court, e.g. for child support or custody issues, everyone must be tested in person with proper identification. Since many labs are affiliated with others, the parent and the child can be tested at different locations. A chain of custody procedure makes certain that the correct samples will be compared.
If a paternity test is only needed for personal information, my DNA advice is to use home test kits. Just make sure the person you want to test actually provides the sample. When there’s a good chance the result will be negative, my DNA advice is to consider this inexpensive but powerful alternative to conventional paternity testing. The extra information may lead you to the right answer.
Many labs market the same paternity test technology as a “sibling” or “kinship” test. Since there are few required values with any relationship beyond parent and child, all such testing can do is calculate the probability of a close relationship. Results are frequently inconclusive.
My DNA advice? Now that the autosomal DNA tests mentioned above can measure relationships far more accurately, don't waste your money on these old technology tests.