Updated on: August 4, 2020

To the end consumer, DNA testing is reasonably straightforward; follow the instructions on the kit and let the service tell you about your genetics. However, advanced technologies power affordable at-home DNA testing, something that would have been impossible only a few decades ago. This guide will run through DNA testing 101:

  • What DNA is
  • How it works
  • Who should undergo a DNA test
  • How to do a DNA test
  • What to do immediately after

The concept of genetics started over 150 years ago, with experiments on pea plants by Gregor Mendel. The field has evolved into a refined science with humongous strides, especially over the last two decades. The first human DNA test was completed in June 2000 at the cost of an estimated $150 million

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What is DNA?

Let’s begin with an overview of what DNA is. DNA is…

  • One of the building blocks for human life
  • Contained within every living cell
  • A chemical blueprint that directs the actions and growth of each cell
  • Packaged into, and protected by your 46 chromosomes
  • •Inherited from your parents

Every cell in your body contains DNA. Those genes were copied in equal measure from each of your parents, but the combination of your genes is unique unless you are an identical twin. It’s the inheritance of DNA that results in some traits or disease being genetic. It’s also how you can trace your DNA backward and explore your ancestral roots. 

GoalTrace Father’s LineTrace Mother’s LineFind Family
TestY-DNA testmtDNA TestAutosomal

Who should undergo a DNA test?

There isn’t a right or wrong type of person to undergo DNA testing. 

Genetic testing is safe and it’s an option for anyone who wants to learn more about themselves regarding health or heritage. 

However, before taking a DNA test, it’s important to understand the pros and cons of genetic testing and to fully understand what a test might reveal. For some, genetic testing opens a Pandora Box they would’ve been happier leaving sealed.

At-home DNA testing is fun and informative, so if you believe that learning about health risks or exploring ancestry could be painful or difficult for you, it’s probably better to forego testing.

How to do a DNA test?

DNA test kits vary from company to company, but most follow a general procedure:

How to Take an At-Home DNA test

  1. Order Your Kit

    You’ll want to research your options and narrow down the selection based on customer reviews and your personal needs. Most services let you order online and receive your test kit in the mail.

  2. Receive the Collection Kit

    Once you receive the kit, it’s time for DNA collection. You’ll take a cheek swab or spit into a tube. Each kit comes with a set of instructions to follow for DNA collection and submitting your sample.

  3. DNA Lab Receives and Process Your DNA Sample

    The testing lab extracts DNA from the cells you submitted and scans them for thousands of variations throughout your genome.

  4. Analyze Your DNA Data

    This final step makes it possible for you to learn more about yourself from the sample you submitted. The testing company will provide you with results based on medical research and its database of other samples. Depending on the test you used, you’ll gain access to information about your medical risks and your ancestral lineage.

Once you get your DNA data -

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We’ve compiled a list of dos and don’ts for anyone undergoing a DNA test:

Do:

Protect your data
Make sure you know how your DNA data will be managed, secured and whether or not a company will share it. Your DNA is a blueprint of you and you should do everything you can to protect it. Every service has an option to download your raw DNA data and then delete it from their database. Once you’ve done this, consider deleting it from their system.
Download all of your data
You never know what is going to happen to DNA testing companies or data. Considering that it is your data, even if you can’t understand or decipher it, you should always have your backup. Every service has an option to download your raw DNA data for an extra level of safe-keeping.
Upload your data to other reputable DNA sites
Manually sharing your test results with other databases helps you get a more comprehensive look into your results. Just remember exposing your DNA data to more parties means you’ll need to take further precautions.
If you’ve opted for health-related analysis, explore your outcomes
At-home testing is not meant to be diagnostic. If you learn about a health concern, don’t panic. Share your results with your doctor and discuss your options. You should never use at-home DNA testing alone to make important health decisions.
Review your shared matches
Your DNA test results can be used to confirm suspected relations or explore your family tree. It’s rare, but you could find long-lost relatives or notable ancestors as a result of DNA testing.
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Don't:

Give too much weight to the results
At-home DNA testing is cheap, easy, and fun. It can also provide important information. But you shouldn’t be making important health decisions or significantly changing your life based on results. 

It’s also important to remember that DNA tests like 23andMe don’t take your lifestyle into account. You might already be managing your genetic risk for certain diseases, so there’s no need to worry.

View your DNA test results as a starting point for improving things, but don’t see it as the end-all-be-all for informing your decisions.
Assume the results are static
Companies regularly update their algorithms based on current science. They also update their databases as more people submit their results. Checking on results periodically can give you new information. Weigh these updates against whether or not you delete your results for security reasons.
Draw hard lines with ethnicity results
DNA testing results can point you in the right direction regarding ethnicity, but won’t give you a complete picture. Again, these tests are a good starting point but don’t provide all of the information you’ll need.
Leave your data with the site indefinitely.
Despite the potential to learn more from database updates, it’s still a good idea to delete your raw data once you’ve downloaded it. Data breaches and leaks occur and you should do what you can to protect your personal information.

How accurate is the DNA test?

It depends on whether you are talking about ancestry or health accuracy. In either case, there’s no easy answer. Let’s consider this question about accuracy based on your reason for taking a DNA test.

Ancestry Accuracy

DNA testing is great for finding a closely related family member. Most tests can reveal first and second cousins or closer relatives who have taken the same test as you.

But modern-day tests fall short of revealing specific information about your ancestry and ethnicity if it goes beyond close relations. You won’t discover specific locations where your ancestors lived by taking a test but might find out the general region from which they lived.

Health accuracy

For 23andMe to include genetic health reports, it underwent a lengthy FDA approval process. The company had to show its results could be reproduced 99% of the time in clinical labs. 

Unfortunately, not all of the results are not immediately actionable or even understandable. 23andMe offers tutorials before allowing you to see health-related risks and predispositions, but that doesn’t mean you should base important health decisions on your results. 

The best you can do is get general information from your results and discuss them with your doctor.

What are the most popular DNA testing services:

CompanyDatabase SizeSales (est)
Ancestry.com15 million14 million units sold
23andMe10 million5 million
Family Tree DNA1 millionUnknown
MyHeritage DNA2.5 millionUnknown
AfricanAncestry.comUnknownUnknown
Living DNAUnknownUnknown
National Geographic DNAUnknownUnknown
HelixUnknownUnknown
Joel is a writer with a passion for the science of DNA and the power of its manipulation.

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