The Pros and Cons of the Top DNA Testing Methods

Top10.com StaffByTop10.com StaffJul. 11, 2019
DNA Testing Methods
Contemplating taking a DNA test? There are many reasons why you might be considering it, including finding out more about your ancestry, checking the paternity of your child, or screening for health issues. Today, DNA tests are so easy to do and affordable that there’s little reason to hold back.

What’s more, DNA testing is practically a DIY affair—all you need to do is order a testing kit from a reputable DNA testing company, take a sample of your DNA, and mail it back to them. The company then sends it to a lab for analysis. Some companies even offer to pick the sample up from your home.

The DNA testing company you choose will depend on:

  • What are you testing for?

  • How fast do you need results?

  • What method do you feel most comfortable with?

Keeping these 3 things in mind, read on to find out more about the most popular DNA testing methods.

Saliva Sample

This probably doesn’t need any explanation, right? A saliva sample is exactly what it sounds like—when you get your DNA test kit, you simply spit into the provided tube, filling it until the marker. Not very elegant, but that’s the way it is. 

Video: https://www.youtube.com/watch?time_continue=116&v=3oTaydRPm3w

After you add saliva till the marker, you’ll need to unscrew the funnel and replace it with the provided cap that contains a buffer fluid. Put the cap on immediately so that it doesn’t degrade the quality of the DNA sample. Then shake the tube gently and place it in the return packaging. Make sure not to eat, drink, chew gum, smoke, or brush your teeth for 30 minutes before you take the sample.  

Saliva samples are typically required if you’re doing a DNA test to check for ancestry or health markers, including lupus, obesity, breast cancer and Type 1 and Type 2 diabetes. Futura Genetics and 23andMe offer this kind of testing.

Cheek Swab

Cheek swabs are the most common type of DNA test for people who want to research their ancestry and in paternity testing. The DNA testing kits used by ancestry research companies like MyHeritage and LivingDNA work via the cheek swab method, while many companies offer paternity testing via cheek swab. 

Cheek swabs are also a good option for people who have trouble spitting, like infants or the elderly, and for whom a saliva sample would be difficult.

A cheek swab is really easy to do, and it requires the same protocol as a saliva sample—no eating, drinking, smoking, etc. for 30 minutes before the test. 

When you’re ready, you’ll open the vial that contains the buffer liquid, take the swab and scrape the inside of your cheek. A proper swab includes moving it up and down while rotating it with your fingers on the inside of your cheek. Make sure not to drop the swab or let it touch anything except your cheek! 

When you finish, put it immediately in the vial, seal it, and shake it gently to mix the sample with the buffer liquid. Place it in the packaging and it’s ready to ship to the lab.

Blood Test

Because saliva samples and cheek swabs are so easy to do, there aren’t many reasons to take a blood test to explore your DNA. The most common reason people choose this type of testing is if a pregnant woman isn’t sure who the baby’s father is. In this case, Non-Invasive Prenatal Testing (NIPT) is an accurate, safe way to find out. 

As opposed to invasive procedures like CVS (Chorionic Villi Sampling) and amniocentesis, which come with a risk of miscarriage, NIPT comes with no risk and is fairly accurate. All that’s needed is a cheek swab from the potential father and a blood test from the mother. Once the fetus is 8 weeks or more, the cell-free fetal DNA in the mother’s blood can be matched with the potential father. 

Hair & Other Testing

DNA can be obtained from samples of hair with the root attached, semen, blood stains on fabric, fingernail clippings, gum, razors, cigarette butts, and more. If this sounds like something from a Law & Order episode, you’re not far off. This kind of DNA testing is often used as forensic evidence in crimes, not for exploring your ancestry. 

But it’s not only for criminal cases—DNA testing from hair and other things is sometimes used when a cheek swab isn’t able to be obtained. This is often called “discrete testing” and is offered by some DNA testing companies. However—and this is a big however—there can be real legal implications if you test someone’s DNA without their consent. Which means, if you want to find out who the father of your baby is, you can’t pluck a strand of his hair and send it in for testing—you must get his consent.

Accuracy of DNA Testing

The accuracy of a DNA test doesn’t depend on how you get the sample, but rather, on 2 things:

1. The integrity of the sample 

When taking a sample at home, you must follow the directions carefully; otherwise, you risk contaminating it and skewing the results. If you need a blood test, make sure it’s done by a medical professional. 

2. The company performing the testing

Not all DNA testing companies are created equal, so you’ll want to make sure you choose one that has a good reputation and uses high-quality labs for testing. Respected companies generally get more accurate results because: 

    • Their staff knows how to handle the DNA sample when it arrives and avoid contamination

    • They employ experts who use proper methods to analyze chromosomes, genes, and proteins—and how to interpret these results.  

    • Have larger database pools in which to compare ancestry markers

As for what you’re testing for—whether it’s ancestry, paternity, or whether you’re at risk for certain diseases—this matters less in terms of accuracy, as long as you choose a solid company. 

The one thing to note is that if you’re testing for illnesses, beware of false positives. A study conducted last year found a high rate of false positives when doing at-home testing for health markers. Practically, this means that if a DNA test comes back showing markers for certain medical conditions, don’t take action until these markers have been retested and confirmed.

DNA Testing: Worth It?

While DNA testing isn’t perfect, for many, the benefits outweigh the risks. People who take DNA tests to find out about their ancestry can use that information to connect with their family roots. People who take DNA paternity tests can finally get the peace of mind they’ve been craving. And those who take DNA tests to check for health markers can proceed to take care of any issues that arise. 

All in all, DNA testing is easy and has the potential to yield positive results. If you’ve been on the fence about it until now, it’s a good time to take the plunge.

Top10.com StaffByTop10.com StaffJun. 18, 2019
Our editorial staff is comprised of writers who are passionate about the world of genetic testing. We specialize in simplifying the process of choosing the right DNA testing kit for your needs.