Mitochondrial DNA (mtDNA) is distinct from the DNA that comprises most of our genes. Mitochondria, small organelles that function in energy production, contain their own DNA. In addition, mitochondria are inherited solely from the mother, so only maternal lines can be traced using mitochondrial DNA. A variety of companies perform mtDNA testing for the purpose of tracing ancestry, and genealogists are using these tests to help flesh out their distant family history and find unknown relatives.
Contact a DNA testing company, such as Family Tree DNA or Oxford Ancestors, for a free DNA testing kit.
Collect a sample of your mtDNA. This generally involves taking a swab or scraping from the inside of your cheek and sealing the sample in a vial provided in the test kit.
Learn about the ancient clan your maternal ancestors came from. The results from the DNA testing company will give you an indication of which of the original clan mothers was your ancestor, if you are European, or where your ancestors might have migrated from if you are of a different ethnic group.
Check your mtDNA against other people's to find those who share your genetic code. You can find databases of others who have taken the same DNA tests on company websites as well as general ancestry sites, such as Ancestry.com. You may discover branches to your family tree that you hadn't known about. Or you may learn that people who share surnames from your family history are not, in fact, related at all.
Compare your mtDNA results with personal family history passed down through written or oral records. Sometimes family history hints at ancestors who came from a specific area. The results from mtDNA testing can be used to determine if these family stories are accurate.