Tracing one’s family history is a favorite pastime these days. But inevitably you find yourself running into dead ends. Technology, once again, can save the day. familytreedna.com offers three basic genetic tests — all based on the analysis of cheek scrapings — that can be used to determine heredity. The most widely used one is the Y-chromosome test, which traces the father’s paternal lineage. There’s also the “Maternal Match” test (or Mitochrondial DNA test), and a test for the “Cohanim gene,” which is of particular interest to those tracing Jewish roots. The results of the tests are added to the site’s Surnames Database Library as reference, and ancestry is proven when the genetic markers of one person match perfectly with someone else’s. Genetic Test Kit, $219. www.FamilyTreeDNA.com