Things to Know Before You Take a DNA Test

What You Need to Know BEFORE You Take a DNA Test

Interested in your ethnicity or hoping to find relatives? Then DNA testing could be for you. But there are some things you should consider, before you take a DNA test.  Let’s get to the bad news first!

It’s important that you are aware before you take the test, that your result may not be what you expect. Even if you think you know what your results will be, you may get a surprise outcome. Sometimes the surprises are joyful and can be embraced, but other times they can cause distress or family conflict. The most common unwelcome surprises are unexpected paternity, siblings not being biological or previously unknown adoptions in the family.  So, be aware that nothing is certain in what is going to be revealed in your test. You need to be open to all possibilities.

Now to the good news! For the vast majority of people, the family relationships will be as they expect and they can enjoy learning about their admixture (ethnicity results), finding relatives through exploring their shared matches and using this information to develop their family tree.

DNA testing is a complex ethical area. I recommend everyone considering having their DNA tested, read the company’s Privacy Statement and make sure that you are comfortable with how the company uses your DNA, before proceeding with a test. This is the reason I only recommend using the major companies listed below – their Privacy policies are clear and public, and they have stringent practices to treat your DNA securely. It is in their interests to ensure customers feel safe! Some companies explicitly do not work with law enforcement agencies or they may ask you whether you would like to opt-in or opt-out of sharing your data with law enforcement agencies. 

Once you have decided to take a test, then it is important to take the right test for your needs.

Which DNA-testing company should I use?

First, you need to be clear about why you want to be tested. Are you interested in your ethnicity, do you want to find shared matches to help you develop your family tree, are you trying to find biological relatives, are you interested in health information or is it a combination of reasons?


 Ancestry is a great starting point for most people who are focused on genealogy. It provides sound ethnicity information, including useful clustering information where concentrated matches exist. It has the largest worldwide database of individuals and the easiest to use Shared Matches system. For anyone trying to locate biological relatives, Ancestry is definitely the first place to start.  However, Ancestry does have its limitations compared to the other companies. It does not offer a chromosome browser for easier and more accurate matching, nor does it offer Y-DNA testing for men (which traces the direct paternal line only)  or mtDNA for women and men (which traces the direct maternal line only). 


If you are interested in European matches, then I recommend testing with Ancestry initially and then uploading your Ancestry DNA data to MyHeritage, which has a significantly broader number of European individuals tested in its database. MyHeritage also has the benefit of a chromosome browser which is a very useful tool for delving deeper into your matches. Ancestry and MyHeritage used together are very powerful in finding out family tree information.


23&Me provides accurate ethnicity information, has an excellent chromosome browser and comparison tool, but although you may find you have many DNA matches, it is rare that they are able to be used easily. 23&Me is USA-centric and historically has been used for people interested in health information from their DNA – consequently a lot of testers have not provided genealogical information and do not wish to be contacted about it. 23&Me is developing its genealogical focus and offers some excellent features, but at this current time it is still difficult to use as a shared matching company. It does offer unique features such as a suggested tree, based solely on your matches, and an ethnicity timeline of when ancestors may have entered your tree. I recommend 23&Me only for experienced DNA users and family historians who have tested elsewhere previously.


If you have predominantly historical UK heritage, then LivingDNA is an excellent choice for learning more about the British counties where you originate. It is excellent for verifying your paper trail and showing areas where you might have gaps in your tree. The company is currently undertaking a lot of work on shared matches – watch this space! At the moment, the matches are not that easy to use, but I expect this will improve significantly over the next twelve months.


If your needs relate to clarifying paternity, then FamilyTreeDNA is an excellent choice. Family Tree DNA offers the traditional autosomal testing like every other company, but they specialise in male Y-DNA testing which can only track a man’s father, and his father, and so on. They also offer matrilineal line testing, for both men and women. Within FamilyTreeDNA are groups studying unusual or difficult surnames, such as ‘Smith’, to try and sort out the relationships. These could be useful depending upon your circumstances.