DNA Paternity Tests

“You are…”

*Pregnant pause, while the audience holds its breath. Shot of the mother’s certain face. Cut to potential father’s bobbing Adam’s apple, a very avatar of uncertainty as he swallows, and for half a second, we’re not sure whether the anxiety is because he wants to hear one thing, or because he needs to hear another.*

“…the father of this child.”

*Cue audience reaction – cheers, gasps, outraged hissing, depending on circumstances.*

We all know this scene, whether we’re avid watchers of daytime TV or not. Chat show hosts have been poking their noises into people’s business for years now, and the big paternity reveal following a DNA test is a trope of the genre. It’s life-changing science, played out as an arena sport.

Life. Changing

Why do we bring this up?

Because it is precisely that – life-changing science.

Science so inherently dramatic, it’s been used as high reality-TV drama. Paternity, irrespective of the past or present of a relationship between two people, changes lives. It connects people, whether just financially or whether in some more emotional way.

And if you ever want a DNA test to be right, to be accurate, to be unfailingly, hand-on-heart, I-cannot-tell-a-lie true, you want that certainty with a paternity test.

In a sense of course, you want all DNA testing to be accurate.

Once Upon A Time…

DNA testing is that unusual thing – a key to the storybook of your family history.

Were your ancestors from Ireland or Uzbekistan? Were they Jewish, Muslim, cobblers or convicts? Whatever your DNA reveals about the journey of your genetic material, it will have a thousand stories attached. 

And once you know, you feel like a part of a very particular story. A very particular journey. If you buy into a journey being a part of who you are, and then you find out that the DNA test wasn’t that accurate after all, and you’re actually descended from a long line of bakers from Braintree in Essex, it’s going to come as a big shock.

Not that there’s anything wrong with coming from a long line of Braintree bakers – it’s just not the journey towards ‘You’ that you were led to believe you were part of.

So most DNA testing is wonderful, and connective, and powerful in ways you won’t really understand till you have your own results.

The Difference

But paternity is very, very different.

Paternity is right here, right now. Paternity’s a journey that can connect you to a life that’s yet, for the most part, to be lived. Or, if the test is negative, it can complicate your life in whole new ways you may not have even considered.

Paternity tests of course can be of use to any number of people. Mothers, or expectant mothers, needing certainty over what the future holds. Fathers, or potential fathers, who need a chapter opening or a book closing. And children themselves, when they need answers which no-one can give them with an acceptable certainty.

No-one apart from their genes, and the genes of those who made them.

Each type of person will have different needs from a paternity test, so finding the right one for any particular case will become a question of which test best meets those particular needs.

Paternity’s a test you take for certainty or for peace of mind. It’s not a test for the faint-hearted, but it can help pave the road that led to you, or it can pave the road ahead of you one way or another.

That’s why, more than any other storytelling DNA test, paternity testing has to be right.

Comparatively Speaking

Of course, paternity testing is different to most commercially available DNA testing kits in one important respect.

Most DNA testing kits require only one sample, and their results merely report what is seen. This is your sample. It shows you have 83% English heritage, 7% Serbo-Croat, 4% West African and the rest, Western European.  That gives you connection to four story-strands to be sure, but it’s merely a report of what is there.

Paternity tests need two samples at least, because their aim is to show a direct genetic relationship between one and the other.

That means that paternity tests come pre-loaded with immediate significance, and are rarely undertaken for the fun of self-exploration. You don’t take a paternity test to find out fun things about yourself on a random Wednesday.

The impact is stronger with paternity tests – and so is the need for consent. Any potential fathers, and the child, and possibly even the mother, will need to be tested to achieve a positive result.

Legal Tests Vs Peace Of Mind Tests

There’s also an entirely miniscule likelihood that you as the person asking for most DNA tests would have anything to gain by faking the results. You want to find out basic information about the journey of your genetic material.

With paternity tests, there’s always the potential that someone will want the results to say one thing or another, to the extent of potentially interfering with the test. That leads to a peculiar legal situation with paternity testing.

Any DNA paternity test you do at home is classed as a ‘peace of mind’ test. It can’t be used in a court of law to establish paternity. It can’t be used that way because there’s no guarantee of impartial testing, and any lawyer worth the name would be able to interpose doubt at various stages of the process.

So be aware – if you need a DNA paternity test that can stand up in court as proof of a contested paternity, you’re going to need a more clinical DNA test, conducted in the presence of an impartial third party witness.

That said, there are plenty of at-home DNA paternity kits that don’t involve dragging all parties into a clinical, awkward and potentially relationship-changing scenario. The range of accuracy, price, method and analytical time is quite broad, so there are options for almost everyone.

If you just want a confirmation of direct genetic connection between a father and child, they’re still potentially very useful – which is why they’re known as ‘peace of mind’ tests.

Have you ever wondered what a DNA paternity test is? What happens? What it actually tests for? How it can determine, with a reasonable degree of certainty, when someone’s the father of a child, and when they aren’t?

How Do Paternity Tests Work?

Whereas a simple DNS test tells you everything it finds about the make-up of your genetic material, a paternity test focuses on the similarities between the genetic codes of the child and the potential father.

This is more of an achievement than you might imagine. You’ve seen the headlines – humans share more than half our genetic coding with a banana, which is remarkably less than helpful.

In terms of protein-encoding genes, every human on the planet shares about 85% of their DNA with mice. Domestic cattle? The stuff of boots and burgers? 80% similarity to humans when it comes to genes.

Sobering thought for fast food lovers, not a whole lot of help for identifying paternity.

By the time we’re talking about just humans, we’re playing in a very shallow paddling pool indeed.

Of around 3 billion genetic base pairs, more or less 99.9% are the same. For every. Living. Human.

You’d think that would make identifying a particular father-child pair almost ridiculously difficult, complex, expensive and time-consuming, wouldn’t you? If 99.9% of the DNA record is notably the same for every human being on the planet, surely identifying one human from another at the genetic level must be absurdly difficult.

Again, the difference between most DNA tests, telling you what you are, and paternity tests, telling you who you’re from, seems to raise its head.

Like, Clue-Codes

The good news is that within that 0.1% of genetic differentiation, there are what might be called ‘clue-codes.’

Nobody actually calls them that; they’re actually called ‘regions of variable numbers of tandem repeat,’ but we’d save that for when you’re trying to sound scientific and cool if we were you.

You can also call them ‘23 highly polymorphic genetic marker couples,’ if you like, but really, trust us, ‘clue-codes’ is as much as most people need to know. They’re regions of the DNA profile where groups of genetic markers identified by letter, say A-G-A-T, are repeated multiple times in the same sequence.

They’re sensationally, almost whimsically meaningless, these ‘regions of variable numbers of tandem repeat,’ – for the most part, they don’t technically affect our development at all, and are not read as instructions by our cells. If anything, they’re akin to verbal tics in the DNA code.

Like, imagine, y’know, a person who like says ‘like’ in, like, every, y’know, like, gap of every, like sentence. A simple verbal tic, but ‘like’ is also a four-letter sequence. If you knew it was a characteristic of one particular writer, you could run a Control+F on any page, and find the word, or sequence, repeated a number of times.

The same is true of any other repeated sequence of letters.

Now, everyone uses the word ‘Like.’ It’s by no means a special sequence of letters. Reading the word ‘Like’ also doesn’t instruct your body that you must like the piece, or the page or the writer. It’s just a recognisable sequence.

But just imagine for a second that one writer put the word ‘Like’ in everything they wrote. Exactly the same number of times.

And that they also put the word ‘What’ in every single thing they wrote, the same number of times.

And ‘This.’

And ‘What.’

Each word its own number of times, but always the same number of times, in any piece of writing, large, small or middling.

That’s more than a style. That’s a signature.

By the time you have a handful of these sequences, repeated exactly the same number of times in every piece, you don’t even need to read the other words, the other, say, 99.9% of the text.

Sure, it’s probably interesting, but in terms of identifying the writer, you don’t need it. You can run your scans, find the right-number-of-times-repeated words, and know the writer who wrote the piece. You can spot the clue-codes, and identify the individual who contributed them to the page.

That’s half the process of a DNA paternity scan.

Great, Now Do It Again. A Lot

Half the process, because any human being, be they foetus, child or grandma, has DNA with what’s often said to be ‘half’ its content from their mother, and ‘half’ from their father.

What that means, in our example, is that there are two copies of what it means to be a human in every single person – one from their mother, one from their father.

And the child, the product of the mother and father’s big zygote adventure, will have identifiable clue-codes from each parent. If their mother used ‘Like’ 8 times in everything she ever wrote, and their father used ‘That’ 6 times in everything he ever wrote, imagine for a moment that the child would have the ‘Like x8’ repetition marker in their DNA, and also the ‘That x6’ marker.

Repeat many times with many clue-codes, and take it down to the level of DNA markers, rather than writing styles, and what you have is a simplified version of how DNA paternity testing works. If you test the child’s DNA for instance and find a ‘This x8’ marker that neither the mother, nor the supposed father have, while none of the ‘That x6’ marker is present…it may be time to have some conversations.

Babes In The Womb

Of course, there are also occasions when the child needs to have their paternity decided while they’re still in utero.

There’s an invasive, and decisive way to do this, but you’ll commonly need to visit a hospital to get it done via amniocentesis.

There is however a non-invasive way of deciding who the father of a foetus is, by testing a small amount of the mother’s blood.

From around the 7 week stage of pregnancy, there’s a minimal – but testable – amount of foetal DNA in the mother’s blood, so that can be tested for repeater sequences that the mother doesn’t have, giving us the genetic identity of the father with a strong degree of accuracy.

What To Look For In A DNA Paternity Test

So now we know what actually happens when you send away your genetic material for processing in a paternity test.

But there’s more to paternity testing than the process.

If you’re going to get it done through a ‘home’ testing kit, there are a few important things to take into account.


As we said earlier, unlike most DNA testing, where information that’s at first unclear or confusing can be allowed – even expected – as part of your DNA journey through your own family history, paternity testing needs to be right.

Ideally, it needs to be right first time, because the impact of inaccurate information in paternity testing can be intense, and personal, and blow people’s real life worlds apart.

Look for companies with a strong record in getting the results right first time. Look for any information about times when they got it wrong. Look into the processes they follow to get your testing done and the results back to you.

It’s impossible to make a strict correlation between companies that have survived in the DNA paternity testing market for many years and smaller likelihoods of error or incorrect paternity information being sent to you. That said, simply by virtue of longer time and probably higher testing volumes, it’s likely that older, more established testing companies will have more presentable evidence of having done the job correctly.

There are always going to be statistical anomalies in any system – tests which are wrongly conducted, tests which get mixed up. And there are also always going to be anomalous results based on unusual circumstances. But the more certain you can be of a company’s record in correct testing and the delivery of cast iron, genetically-proven paternity, the more value the paternity test will have.

There are plenty of times in life when ‘close enough’ will do.

Paternity testing’s not one of those times. Correctly-established paternity can have financial impacts, contact impacts, and can reshape the reality of your future in ways you may not know until they happen.

If you want legally impregnable accuracy, you’re going to have to go the third-party witness route. But for personal peace of mind – or at least a direction in which to go from uncertainty of mind, choose a company with a strong reputation.  


There are any number of reasons why getting the result of a paternity test may be extremely time-sensitive.

Like many things in life, faster is always better in terms of paternity-certainty – assuming the speed doesn’t compromise the accuracy of the test. So, shop around. See which companies have the best accuracy results, first and foremost.

But then check their speed of return too. Waiting weeks may significantly change the situation around you, to the point where paternity results may become irrelevant as far as your decisions are concerned.

Getting the most reliable data with the fastest possible turnaround time is worth paying extra for - if you can afford it.

Ease Of Use

The method of testing is rarely going to be as important as the first two factors. But be aware there are several methods available from different companies.

You can test for paternity through DNA collected in a saliva sample, through a small blood sample, or through the most popular method, a simple cheek swab.

The method of collection can sometimes have impacts on the turnaround speed of the results.

It’s also worth noting that you have a certain responsibility for speed yourself – take the sample, and then return it as fast as possible to the testing company, so there’s as little latency, or delay, in the process of getting your samples tested. DNA is legendarily tenacious stuff – it’ll stay around long enough to catch killers and tell stories – but still, faster is probably better for everyone concerned.

While this is not something that can be controlled by the various companies offering DNA paternity testing, it’s also worth considering how willing or unwilling various people can be to a) give up their genetic material at all to a commercial operator, and b) give up some kinds of genetic material.

It might, for instance, be far easier to get a potential father to submit saliva for testing than it would be to get them to submit to a cheek swab. It’s worth considering the real life collection difficulties before you opt for a DNA paternity test that demands genetic material in a particular form.


DNA testing for paternity is not a thing to skimp on by any means. Certainty, accuracy in this test can change the shape of your life and the lives of those around you.

That said, there are a variety of pricing models on the market, to meet every need. Some are simple, one-off tests of the very specific DNA selection you send off. Some tie you into subscription models – though very few, it’s true to say, offer regular DNA paternity testing options.

But you can get access to databases of family history information in some cases, in case you’re aiming to trace your family line back through the generations from a paternal starting point.

Again, the best and soundest advice would be to shop around. Discover what different providers offer, and decide what you actually need from your paternity test. That will be a great ready reckoner of what you’re prepared to pay – and what you expect to get for your money – a thing you may not have actively considered until the day you found it was necessary.

It’s also worth noting that the cost of paternity DNA testing can vary hugely from some home kits to others, and most of the cost differential will be accounted for by reputation and additional offerings (paternity-plus, if you like), so keep your budget in mind, go for accuracy and company reputation first if possible, and decide on any potential add-ons, subscriptions or extras as – at the very least – a secondary concern.


It goes without saying that DNA paternity testing should be a private affair. Some people are especially nervous about surrendering their DNA to a commercial operation though.

If you or anyone you’re getting tested is especially sensitive to the security and privacy implications of their DNA being held and essentially experimented on, it’s worth being able to find and quote your chosen tester’s policy.

Make sure you’re clear about who sees, identifies, stores and/or destroys your genetic samples. Make sure there is a clear policy that’s adhered to, and that you’re aware of the procedure before you spend your money on one DNA paternity test over another.

Checklist your Process

Bottom line, there are two leagues of paternity testing. There’s the court-robust, third-party witness version, which is what you’ll need if paternity is contested, and things like maintenance payments, access and visitation rights are in question.

Then there are the ‘peace of mind’ options, which are the result of DNA gathering, posting and assessment by a company lab. Even among those peace of mind options, the choices can be mind-boggling and the prices can vary significantly without necessarily explaining where the rest of your money has gone.

Finding the right DNA paternity test for you depends on the specific circumstances in which you need one.

We’d recommend following this quick checklist to find the test that meets all your needs.

Legal or Peace Of Mind

  • Test matches the level of certainty you need


  • Company reputation
  • Depth of analysis
  • Degree of published certainty of test results


  • Useful window of return?
  • Speed matched with effectiveness of testing?

Ease Of Use

  • Collection method matches your lifestyle?
  • Discretion of result-sending a necessity?


  • Affordable?
  • Worth the price, compared to other tests available?
  • What’s the difference I’m paying for?
  • Do I need to pay extra?


  • Discretion of results-return, if needed?
  • Clearly defined policy on DNA storage or destruction?
  • Record-keeping? 
  • Whatever choice you make on DNA paternity testing, we’re here to help you make sure it’s the right choice for you.

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