Are Home Paternity Tests Accurate?

There was a time when getting a DNA test was expensive, complicated, and usually reserved for scientific research or police investigations. But over the years DNA testing technology has rapidly improved, making tests quicker, more affordable, and more accessible to average members of the public.

If you have doubts over who’s the real father of a child, you can now buy a home paternity test kit from a pharmacy, grocery store or online – and administer the test yourself in the comfort and privacy of your own home. They’re also a lot cheaper than many people believe – the most basic type of paternity test start from around £100 or $120. You simply provide a DNA sample taken from the inside of your cheek, sign all the paperwork and mail the kit back to the testing laboratory. A few days later, you receive your results. Sounds simple, right?

But are these home tests accurate? Are they as reliable as a test performed by a doctor in a hospital? This is a fair question to ask, as having a DNA test can have possibly life-altering ramifications for you, your partner and your family.

Here’s everything you need to know about getting a home DNA test…

Is the testing company accredited?

Do a quick Google search for “home DNA testing” and you will find dozens of commercial testing labs with enticing offers and prices. But unless a testing company is accredited, there is no guarantee that the test will be accurate.

Whichever company you choose, be sure to check their accreditations. There are 2 particular quality marks to you should look for – ISO 9001 and ISO 17025.

ISO 9001 is the internationally recognized standard for quality management within a business. It ensures that policies and procedures are in place to make sure customer needs and expectations are met.

ISO 17025 is a more specific quality standard that applies to testing and calibration laboratories (such as DNA labs). It ensures that the testing company is technically competent and is able to generate technically valid results.

Why is this important? Without accreditation, for all you know the lab could just make the results up!

Other ways to judge the quality of a testing lab:

  • Do they have positive reviews from an independent source, such as TrustPilot or DNA Testing Choice?
  • Are they recommended by the Government or another official body such as the UK Home Office or the US Department of State?
  • Does the company website clearly display a phone number, street address and a complaints procedure?

Do you need the test for legal purposes?

Home DNA tests are often referred to as “Peace of Mind Tests”. That name says it all – the test results are only intended for your own personal peace of mind. They cannot be used to settle legal matters such as a child custody dispute or an immigration case.

Because you do the test at home with no witnesses, the lab simply trusts you to provide the right DNA samples from the right people. The test is still accurate (as long as the lab is accredited), but the results will not hold up in court.

If you do need a test for official purposes, you need a legal test. The scientific process is the same, but your samples must be taken by a medical professional or a trained sample collector. The collector will check your ID, make sure all the relevant paperwork is complete, and transport the samples back to the lab under a carefully controlled chain of custody.

The results from a legal test will be recognized in court – again, just as long as the lab carrying out the test is accredited. Due to the extra work involved, legal tests are usually a little more expensive.

Why do DNA tests give a 99.99% probability? Why can’t they be 100%?

There are two similar terms we need to talk about here – accuracy and probability.

Accuracy refers to the scientific process. A DNA test performed by an accredited lab will be 100% accurate. However, the test will produce a probability that the two people being tested are related. With a paternity test, the probability will either be 0% (definitely not related) or over 99.99% (i.e. they are related).

Why can’t it be 100%? Because non-related people still share a large portion of DNA – it’s just part of being human. To be 100% sure, you would have to test the child’s DNA against every man on the planet!

But don’t worry – 99.99% probability is still enough for a legal test to stand up in court.

To summarize:

  • Yes, a home DNA test is accurate – just as long as the testing company is competent and accredited.
  • However a home DNA test cannot be used to settle legal matters.