DNA testing has transformed family history research by connecting living relatives and illuminating ancestral origins. This practical guide explains test types, how to interpret results, and how to use them alongside records for reliable conclusions.

DNA testing has become a powerful companion to traditional records, giving family historians new ways to verify relationships and explore deeper lines. In the field of genetic genealogy, test-takers compare segments of shared DNA to identify common ancestors and build evidence-based trees. Many companies market heritage testing that promises to reveal where your forebears lived, but the greatest value of these tools emerges when you combine them with documents, interviews, and careful analysis. Taken together, they can accelerate your research and help resolve long-standing mysteries.

There are three main test types, each answering different questions. Autosomal tests cover all ancestral lines back about 5–7 generations and often include estimates of ethnic origins based on reference panels. Y-DNA follows the direct paternal line and can confirm or refute surnamed lineages, while mtDNA traces the direct maternal line across many generations. Choosing the right test depends on your research goal—for example, adoptees often start with autosomal tests for broad coverage, whereas a surname project might prioritize Y-DNA.

Interpreting your results involves more than reading an ethnicity estimate—it means working with DNA matches. Start by sorting matches into clusters that likely descend from the same ancestral couple, using shared matches and centimorgans to gauge relationship range. Build targeted trees for top matches, look for triangulated segments where available, and correlate genetic hints with records such as civil registrations, parish books, and immigration files. This approach turns raw data into testable hypotheses about your DNA ancestry and helps you place new relatives accurately.

As you proceed, be mindful of limitations and ethics. Heritage testing cannot identify specific ancestors on its own, ethnicity estimates vary by company, and endogamy or pedigree collapse can inflate shared DNA. Obtain informed consent before uploading data to third-party sites, respect privacy settings, and avoid publishing sensitive findings about living people. By pairing sound methodology with the tools of genetic genealogy, you can unlock insights, document lines with confidence, and share a richer family story.