How many DNA tests should I take?

If you've already taken one autosomal DNA test, such as AncestryDNA, you may not need to take any additional tests.  You can download your raw data file and upload it into other test databases.  The DNA Geek created a helpful chart showing which results can be uploaded into which databases.

Which autosomal DNA test should I take?

Family History Daily created an excellent Comparison Guide which may help you decide which testing company best meets your needs.  We prefer AncestryDNA (when it's on sale), because Ancestry has the largest database of test results and is likely to yield more matches.  Ancestry also allows you to assign a Viewer to your DNA results, so we can analyze your DNA results without logging into your account.

Should I ask my family members to test also?

It is always a good idea to discuss DNA testing with your family, because their response can alert you to potential surprises in your results.  The presence of known maternal or paternal DNA matches may enable us to sort your unknown DNA matches more efficiently.  If additional testing is required to confirm your ancestry, we will create a targeted list of individual to ask.

Should I take a Y-DNA test?

It depends.  The Y-DNA test only works on men, because it tests the Y chromosome which only men have.  The Y chromosome is passed from father to son and will therefore only show direct patrilineal ancestry.  If you are searching for the father of your paternal grandmother, a Y-DNA test would only be helpful if you could find a living direct male descendant from that ancestral line: your paternal grandmother's brother or his son or his son's son.  If there are no living direct male descendants or if they decline to test, Y-DNA is not an option.

What is mtDNA?

This is mitochondrial DNA, which is passed from the mother to all of her children.  Both men and women can take this test.  It will only reveal matrilineal ancestry, i.e., your direct maternal line.  This can be difficult to use for genealogical purposes.  The matches may be many generations distant, and women usually changed their surnames.  This test is more useful for revealing ethnic origins.

How can an autosomal DNA test help me find my unknown ancestor?

Autosomal DNA tests analyze specific segments of your 22 pairs of autosomes, which you randomly inherited from your parents.  Some companies analyze your X chromosome also.  Each company uses proprietary algorithms to calculate genetic distance in order to estimate how closely you are related to other people.  These estimates may vary by company.  We use the projected relationships to identify the most recent common ancestor shared by two or more people: for example, a shared set of great-grandparents.  We then use traditional genealogy techniques to study their descendants and identify candidates who could be your unknown ancestor.  In some cases, testing of additional living people may be required to confirm the hypothesis.  In some cases, it may not be possible to identify a specific individual but merely the family group.

How much will it cost to find my unknown ancestor?

This depends on several factors:  the number and quality of your DNA matches, the availability of public records for the applicable place and time, and the degree of endogamy (intermarriage) in your family tree.  If you have a first cousin DNA match with a family tree or a uniquely identifiable name, the search may only require a few hours.  If you have no first or second cousin DNA matches with family trees, the search can be very time-consuming indeed.  Additional time must be allowed for documenting the search results.  This ensures that the research can be verified at a later date.