In Irish genealogical research two crucial pieces of information are the name and its variations, and the geographic area of the family being researched. Once the place of origin is narrowed down then a thorough search of any records for that area can be done. Ideally getting the geography down to a township is the goal. DNA testing can be a tremendous asset in locating the area of a family's origin.
DNA results very often produce matches to related families with records that mention a particular township or village. In this way families that have no idea of their geographic origins can overcome this obstacle and find the area and even the township that their family originated.
DNA results also often show variations in Ulster surnames that can provide important new information for a family's history. For example, a family surnamed McKean may have a match with a family surnamed Johnston. The surname McKean is from the Gaelic name Mac Eáin which was often anglicised as 'Johnston.' In this case McKean and Johnston are the same family and or but two forms of the same surname. Another example is McAmis and McKemmish, a high quality DNA match would tell the two families that their surnames, despite looking quite different, are but two forms of the very same Gaelic surname, in this case Mac Thómais.
Families that emigrated from Ulster very early, during the 1700s, often will have little idea of their surname's original form and while they know the left from Ulster, the actual township, parish, and even County is often not known. With DNA testing, these early emigrant families will have matches to families that emigrated from Ulster much later, in the 1800s or even 1900s. This gives the 18th Century emigrant families access to records of their proven relatives from the 19th and 20th Centuries, which often have very detailed information such as township of origin, religion, languages spoken, etc.
For people of Ulster ancestry, DNA testing and results, can provide the two crucial aspect of family history and genealogy research, name and location. The Ulster Heritage DNA Project provides tools and support for families that use genetic genealogy to get around those infamous brick walls in research.