Best DNA test for 2021: AncestryDNA vs. 23andMe and more Looking for the best DNA test kit and the best testing services? Here are your top options. Driven by higher visibility, lower prices and improving science, DNA testing has entered the mainstream over the past 20 years. A DNA test can help you identify close relatives all the way back to your earliest ancestors, which can kickstart or enhance your understanding of your family history. Though a controversial and thorny topic, some tests claim to reveal your "ethnicity," and some services can shed light on your genetic predisposition for diseases and physiological traits ranging from eye color to your tolerance for cilantro.