DNA Testing Helps Navigate Through Brick Walls
All the DNA tests will provide you a list of close relatives and cousins who you share DNA with. It is a lot of fun to connect with cousins, near and far, closely related and distantly related. You may even unearth hidden family secrets, or knock down some old family brick walls you have been researching.
The larger the testing company the number of matching cousins increases. It is also advantageous to test at more than one company to increase your chances of making connections. Some companies allow you to transfer DNA from or to other companies. The information the testing company provides is also important. Ancestry DNA is the largest database and it provides access to many family trees, often making it easier to figure out a connection. It does not provide health information or specific information on where the chromosomes match. 23 &Me, Family Tree DNA, and My Heritage DNA provide details on where your chromosomes match. This is important if you want to later do Chromosome mapping.
Once you look at a specific DNA connection with a cousin you can work on figuring out who your most recent common ancestors are (MRCA). The DNA you share came from this particular set of ancestors. It is recommended that you note in each great grandparents file the persons who you have a DNA match with where this is your MRCA (most recent common ancestor). Note the size of the match and your relationship. Having this validates your family research and that you are researching the correct family line.