You’ve probably heard of deoxyribonucleic acid — better known as DNA — but could you describe exactly what DNA is? To learn more about what DNA is, perhaps it’s helpful to first answer the question: When did DNA testing start?

DNA Testing in Popular Culture

Much of what we understand about DNA testing is learned through popular culture. When we think about DNA testing, our minds reflexively flash to television shows like CSI or NCIS — or maybe you think about the latest crime novel you read.

Our almost full-time immersion in the world of technology makes it easy to forget that DNA testing has been around for just more than 20 years.

It’s astonishing but true.

In the 1980s, scientists made two DNA-related breakthroughs that make possible all of what we know today of DNA testing. It was during that time that Kary Mullis of the United States discovered the polymerase chain reaction (PCR) and that Sir Alec Jeffreys of the United Kingdom discovered how to solve crimes using DNA fingerprinting.

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What is DNA Fingerprinting?

Sir Alec Jeffreys was knowledgeable in molecular biology and interested in human genetics. He was also looking for a way to conduct more impactful research and scientific experiments, so he combined his knowledge and his interests to begin researching and testing DNA.

His research began in 1977, but it wasn’t until Sept. 10, 1984, that he first discovered DNA fingerprints. He discovered them by chance, and he wasn’t sure at first whether or not the finding would prove meaningful.

He dabbled in using DNA fingerprinting for immigration- and paternity-related applications. He continued to fine-tune his processes. And then, in 1986, a local police department contacted Jeffreys about help with two rape-murder cases.

The First Forensic DNA Testing

The police department was investigating two rape-murders three years apart. They wanted to know whether the crimes had been committed by the same person or if the second was simply a copycat of the first.

Though Jeffreys had doubts, he embarked on the first-ever forensic DNA test. That test led to the apprehension of the rapist/murderer. By 1990, DNA fingerprinting was so well established that it became the standard for genetic testing worldwide.

DNA Testing Today

Today, investigators use Jeffreys’ groundbreaking research for an incredible number of criminal investigations. His approaches are also used to identify birth defects and other genetic conditions, paternity testing, discovery of ancestry and more.

Forensic DNA specifically is used worldwide, serving as the foundation for a wide range of police investigations. It’s frequently applied in sexual assault cases, but it’s also used in homicide situations. Not only does forensic DNA testing help capture and convict assailants, it also helps free wrongly accused suspects — many of who are saved from life sentences and even death row.

Imagine that: The DNA testing that Jeffreys first viewed with skepticism is now used to save the lives of the innocent.

Time Magazine writers that more than 2,000 people wrongly convicted of crimes have been exonerated thanks to DNA testing and the innocence project.

Beyond Forensics and Criminal Investigations

DNA testing isn’t just used by police departments and other institutions. Average, everyday citizens also use it to discover hereditary disorders they could possibly pass along to their children. In other cases, DNA testing helps uncover a mutation that parents carry without it being evident.

Medical professionals can use DNA testing to identify common disorders during pregnancies, including down syndrome, sickle cell disease and cystic fibrosis. Doctors can also detect countless other disorder through genetic counseling.

Identifying Family Members Through DNA Testing

Many families rely on genetic counseling throughout a pregnancy, but others use it after children are born to find relatives and to prove paternity. This kind of testing is often used in cases of adoption or separation, or when someone is interested in learning more about their distant relatives and ancestry.

The use of consumer DNA kits is becoming a more and more popular way to unlock the secrets of personal ethnicity and ancestry. It’s a pretty affordable way, too. You can find numerous providers of such tests, including Vitagene, 23andMe, AncestryDNA and others. We even provided a rundown of the best DNA test for ancestry.

Some of these consumer DNA kits are available for as little as $100. While the ancestry-related results are legitimate, WebMD warns consumers to be more careful about relying on health-related results that indicate the likelihood of disorders and diseases like cystic fibrosis and ovarian cancer.

While many of the more expensive kits offer health-related results, it’s best to rely on these products for ancestry-related information — discovering long-lost cousins or where bloodlines originated.

What Else is Important About DNA?

DNA is the kind of topic that demands a book rather than a blog post. But here’s a look at just some of the things you should know about DNA in general:


How You Look and Act

DNA is something that affects not just how you look but also how you act. It carries a genetic code which certainly determines things like your height, hair color, eye color and complexion. But it also carries information that can determine your personality, sense of humor and temperament.

Most DNA is the Same

Here’s something that most people don’t realize: About 99% of DNA is exactly the same from person to person. Even people you may feel look and act nothing like you do have almost identical DNA to yours. It’s the less-than-1% (called “genetic markers”) that makes each individual unique. Only identical twins are carrying 100% identical DNA.

Test From Anywhere

Your unique DNA is present in cells all over your body, including your hair, skin, blood and bodily fluids. When scientists test DNA, they can use samples from anywhere, and they use a process called “polymerase chain reaction” to copy your DNA and make analysis easier.

Is it Accurate?

It depends. If you’re testing to see if one sample matches another, it’s easy to conclude there is no match. If it appears two samples do match, it’s more complicated. Relatives have highly similar genetic markers, and there’s even a small chance of strangers having similar profiles.

Different Types of Test

DNA tests are typically conducted for one of four reasons. Parental testing determines who biological parents are. Forensic testing is used to identify suspects. Therapy testing is used to identify genetic conditions and birth defects. And ancestry testing identifies heritage.

Analyzing Ancestry

Ancestry testing looks at thousands of markers across your entire genome. This in-depth test helps determine your ethnic origin and ancestry. Find out where your ancestors once lived, and discover cousins and other relatives you didn’t know existed.

DNA Offers So Many Possibilities

This article only scratches the surface of how DNA can be used. In the next 20 years, DNA testing will make significant leaps and help us unlock even more secrets. It’s amazing that a fingertip or a strand of hair can be used to determine guilt or innocence, paternity or the likelihood of suffering from a disease or disorder.

Looking for more resources about DNA and DNA testing? The U.S. Department of Health & Human Services website offers information and outlines a number of resources you can explore.

Also, be sure to check out our piece on the best DNA test for ancestry. Let us know about your experience with a consumer DNA test using the comments section below, or you can always get in touch using our contact page.