DNA tests are relatively simple and all work the same way. After choosing which brand you want to use, the company mails you a saliva collection kit. You simply spit into a tube and mail it back to their lab. After several weeks, you receive your results and learn about your health or family tree in detail.Most DNA tests (including 23andMe) use genotyping to look at specific locations in your DNA and identify the variations that make you unique. Focusing on any specific variation can lead to clues about your ancestry, health conditions, and other traits.Other tests, such as AncestryDNA, use autosomal DNA testing, which measures your autosomal chromosomes and matches them across a database of people who share DNA with you to find relatives.