How DNA Kits Work and What They Test

Each kit works similarly: You answer a few questions about yourself, order the kit, collect your sample, register it (this is very important), send it back, and wait for the results. That said, they differ in the collection process and, to a smaller extent, the cost of shipping. When we tested 23andMe back in mid-2015, the company could not accept DNA samples collected in or sent from New York State because of local laws (we had to cross the border to New Jersey). The company was also unable to ship DNA kits to Maryland.

The 23andMe shipping issues resulted in part because when the company first launched, it tested for a litany of health issues and genetic markers for disease, raising concerns from the FDA and state agencies. The company stepped back and has been working more closely with governmental agencies as it rolls out more features.

Those restrictive laws are no longer on the books, and 23andMe has expanded its portfolio of tests. Competitors have also started adding health and wellness tests to their offerings, as well. AncestryHealth and MyHeritage DNA offer reports on carrier status and genetic health risks. LivingDNA has a wellbeing kit that provides insight into diet and exercise. HomeDNA tests for a healthy weight, skincare, and food and pet sensitivity.

How to Use a DNA Testing Kit

HomeDNA has the most straightforward DNA extraction process; swab each cheek twice with a cotton swab, and place the swabs in the included envelope. Living DNA and MyHeritage DNA have similar approaches. 23andMe and AncestryDNA require that you spit into a tube up to the fill line (which is more challenging than it sounds), and ship it back with stabilization liquid. Most of the services said not to eat, drink, or smoke for 30 minutes to an hour before testing to get the best possible sample.

The most important part of this process is registering your kit before shipping it. All five services require this, and if you don't do it, you won't be able to access your results. This requirement is to protect your privacy—your name won't appear on the kit or the results—and to easily track your specimen as it goes through the process. Of course, when you sign up for an account with these services, your identity is connected to it, but the sample and any reports stored on the service's end will only have a unique barcode.

Some services cover shipping costs. AncestryDNA's $99 fee includes two-way shipping. 23andMe adds a two-way shipping fee of $9.95 for the first kit and $5 for each additional one. HomeDNA ships a prepaid envelope to return your sample and offers three shipping options: $7 for two-day shipping, $14 for overnight, and free shipping that takes 7 to 12 business days. Living DNA provides standard shipping for $9.95 (5-10 business days) and express shipping for $39.95 (2-3 business days). Finally, MyHeritage charges $12 for shipping, but if you order two kits, you pay $6. And if you order three or more kits, you get free shipping.

Once you've shipped your sample, it's waiting time. All of the DNA testing services we reviewed confirmed receipt of the specimen via email, and most estimated that the results would take anywhere from three to eight weeks to process.

Note that DNA testing isn't the only kind of kit that collects physical evidence from you these days. Ubiome is one noteworthy example. The service evaluates your microbiome—basically the bacteria that live in and on you. In our review, we took its gut biome test, which required our intrepid reviewer to send in a poop sample (insert poop emoji here).

In short, DNA testing potentially exposes a lot of information. Perhaps more than we think.

DNA Results and Family Tree Features

Next, you'll receive an email alert that your results are ready, and that's when the fun begins. Your results may not be as dramatic as those portrayed in TV ads, but you may find some surprises. One important note: Results are different depending on your sex assigned at birth. Women, who have the XX chromosome, can only trace back the maternal line. Men, having the XY chromosome, can track both the maternal and paternal lines, painting a complete picture. If you're a woman, it's worth asking your brother, if you have one, to take a test and share the results. 

AncestryDNA, 23andMe, HomeDNA, Living DNA, and MyHeritage DNA all provide reports of your ethnicity, some showing maps of where your ancestors lived, along with information about the particular countries and regions.

On all platforms we tested, you can initiate a search for relatives. The software continually searches for DNA matches as more people share their results. This feature may be useful if you're building a family tree or looking for relatives you've never met; otherwise, it may be more of a nuisance. You can opt-in or out at any time, and the DNA service doesn't share your contact information. Relatives can message you through the software, though. If you already use genealogy software, you may be able to download your results and upload them to your preferred program. Otherwise, AncestryDNA and others featured here have family tree software that you can easily link.

23andMe started by testing for genetic markers of diseases and medical conditions before rolling that back in response to the governmental concerns. It has since added a slew of health-related features with approval from the FDA. The company offers two options: Health + Ancestry ($199) and Ancestry ($99). The Health + Ancestry plan includes testing for genetic health risks and carrier status, as well as reports on your genetic weight, hair loss, and other traits.

If you're the family-tree manager for the family and want to track DNA results for other family members, you can do so. In some cases, you may have to create a separate account for each kit that you're managing. You can also share your results as well with other members and connect family trees.

Again, be sure to read through the terms of service and any other agreements before proceeding. Don't agree to anything that makes you feel uncomfortable. You might consider watching the video below, too.

How We Test DNA Services

We evaluated each kit by ordering one, just like any customer would, and tracking how long it took to arrive at the lab and get processed. Then we compared the breadth and depth of the results to see what rose to the top. The whole process was a lot of fun, in part because of the anticipation of getting the results. Most of the kits warn that testing your DNA can lead to surprising—even life-changing—results. For example, there's the story of a woman who thought she was Irish, but her DNA test revealed she was also European Jewish, Middle Eastern, and Eastern European. After diligent research, she discovered that her father, who had died years earlier, had been switched at birth with another child. Of course, there's also a good chance that you won't be surprised at all, but there's satisfaction in knowing for sure where your ancestors lived and how you came to be who you are.

Note that it's not just the human members of your family whose ancestry might interest you. The best dog DNA test kits can help you tell a Maltese from a mutt, and we've reviewed the top choices in that category.