4 minute read

The power of next-generation sequencing (NGS) DNA testing

Published June 27, 2023

Did you know that human beings have more than 6 billion individual building blocks in our “deoxyribonucleic acid” code or DNA?¹ And that all human beings are 99.9% identical in their genetic makeup? The differences in the remaining 0.1% of our DNA are what make us unique—and they hold important clues about the causes of disease.²

DNA testing is becoming increasingly popular. Why? Because it provides important genetic information that can help you live a longer, healthier life. It can tell you what health problems you might uniquely face, or that might run in your family, and help you chart a more personalized path to prevent, delay or plan to live with them.

Easy, home collection DNA test from Quest®

Learn more about identifying inherited health risks with Quest® Genetic Insights health test. This test uses a high-tech analysis known as “next-generation sequencing” or NGS. You can purchase this test online without a doctor’s visit and receive a home collection kit. You’ll also have the option to consult with a genetic counselor at no extra cost.

To learn more about what your DNA can reveal about your health, look for additional Quest Genetic Insights tests coming in 2024.

What is NGS?

NGS is an advanced way of analyzing your DNA that can look at millions of DNA sections, or segments, inside your genes, at one time!³ It can take an in-depth look at that 0.1% of your unique DNA using NGS technology. How many times the same segments are examined by the NGS scanner is called “read depth” or “sequencing depth.” And that depth is what leads to greater accuracy of your results.

NGS testing is more accurate than anything that came before. It helps us see information we can’t see using any other technology, with powerful results. The bottom line? NGS is more likely to find changes in DNA, called variants or mutations, than other testing technologies that scan fewer segments and not as many times.

NGS technology vs microarray technology

Many DNA testing companies use a standard technology called microarray. Microarray looks at a limited set of DNA variants, scanning for a smaller number of DNA differences linked to inherited health conditions. Often, there are many DNA variants microarray testing just won’t be able to find.

In the detection of BRCA1 and BRCA2 variants linked to cases of hereditary breast and ovarian cancer syndrome (HBOC):

  • Other tests using microarray genotyping detect 20% of HBOC cases
  • Our next-generation sequencing (NGS) test detects at least 80% of HBOC cases⁴

Quest’s DNA test with NGS technology

A convenient way to identify inherited health risks is with a Quest Genetic Insights health test. It’s a home collection kit that can be purchased online without a doctor’s visit.

Our test uses advanced NGS technology to look for DNA variants in 36 genes linked to 23 health conditions. It includes the option to consult with a genetic counselor to discuss your results, at no extra cost. You can also share the results with your doctor.

Get DNA analysis for:

  • Breast cancer
  • Colon cancer
  • Heart and blood health
  • Heart disease
  • High cholesterol
  • Iron overload
  • Blood clots
  • Connective tissue disorders
  • Carrier status (conditions that can be passed down to your children)
  • Cystic fibrosis
  • Sickle cell anemia
  • Tay-Sachs disease

Does NGS work with blood or saliva?

Yes! While it may be hard to believe, saliva-based DNA tests powered by NGS technology are just as accurate as blood-based DNA tests powered by NGS technology. And they’re far more convenient because you can collect your own sample at home.

You don’t have to worry that the quality of your saliva sample will be affected when you send it to the lab. The sample tube used to collect your saliva contains a stabilizing solution. This solution protects the quality of your saliva for several months, in both hot and cold temperatures.

Why should I get a DNA test with next-generation sequencing (NGS) technology?

You’ll feel more confident in your results and can make more informed decisions about a personalized wellness and prevention plan. You’ll be able to better prevent future health challenges, for yourself and for future members of your family. And you'll be joining a growing number of people who know that it is possible to learn from your genes.

Quest’s NGS DNA testing can help you:

  • Identify common DNA variants that may put you at higher risk for inherited health conditions like breast cancer, colon cancer, high cholesterol, iron overload, and heart problems
  • Learn how your unique DNA may affect your current or future health
  • Find out if you have a genetic variant linked to your family history
  • Share results with your doctor so you can get screenings for early detection of certain diseases
  • Stay on top of preventive care and focus on specific healthy changes that can have the biggest impact on your future health
  • Find out exactly what to do if you have a high-risk result by talking to a genetic counselor, at no extra cost

Watch this video about genetic counseling.


  1. DNA sequencing. National Human Genome Research Institute. Last Reviewed April 5, 2018. Accessed April 3, 2023. https://www.genome.gov/dna-day/15-ways/dna-sequencing
  2. Why are genetics and genomics important to my health? National Human Genome Research Institute. Last Reviewed September 7, 2018. Accessed April 3, 2023. https://www.genome.gov/about-genomics/fact-sheets/Genetics-vs-Genomics#:~:text=All%20human%20beings%20are%2099.9,about%20the%20causes%20of%20diseases
  3. Shendure J, Porreca GJ, Reppas NB, et al. Molecular biology: Accurate multiplex polony sequencing of an evolved bacterial genome. Science (80- ). 2005;309(5741):1728-1732. doi:10.1126/science.1117389
  4. BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. Updated May 26, 2022. In: Adam MP, Ardinger HH, Pagon RA, et al, editors. GeneReviews®[Internet]. University of Washington, Seattle; 1993-2022. https://www.ncbi.nlm.nih.gov/books/NBK1247/


  1. A beginner’s guide to NGS. Illumina website. Accessed April 3, 2023. https://www.illumina.com/science/technology/next-generation-sequencing/beginners.html
  2. DNA microarray technology fact sheet. National Human Genome Research Institute. August 15, 2020. Accessed April 3, 2023. https://www.genome.gov/about-genomics/fact-sheets/DNA-Microarray-Technology
  3. DNA. NCI dictionary of genetics terms. NIH: National Cancer Institute. Accessed April 3, 2023. https://www.cancer.gov/publications/dictionaries/genetics-dictionary/def/dna
  4. DNA sequencing. National Human Genome Research Institute. Last Updated April 5, 2018. Accessed April 3, 2023. https://www.genome.gov/dna-day/15-ways/dna-sequencing
  5. DNA test and genetic testing. Cleveland Clinic. Last reviewed May 21, 2022. Accessed April 3, 2023. https://my.clevelandclinic.org/health/diagnostics/23065-dna-test--genetic-testing
  6. Fatima, Tamseel & Ebertz, Andreas. NGS diagnostics: Range of diseases. Eurofins Genomics. Accessed April 3, 2023. https://the-dna-universe.com/2022/04/07/ngs-a-powerful-tool-for-diseasediagnostics/#:~:text=For%20the%20diagnosis%20of%20complex,et%20al.%2C%202018
  7. Genomics technologies are empowering precision health. Illumina website. Accessed April 3, 2023. https://www.illumina.com/areas-of-interest/precision-health.html
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  12. Key differences between next-generation sequencing and sanger sequencing: understanding when NGS can be a more effective option. Illumina. Accessed April 3, 2023. https://www.illumina.com/science/technology/next-generation-sequencing/ngs-vs-sanger-sequencing.html#:~:text=While%20the%20Sanger%20method%20only,of%20genes%20at%20one%20time
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