DNA Testing Explained: Costs, Accuracy, and Learn About Paternity, Siblings, and Ancestry — Even Before Birth

Medical banner with doctor holding vial

DNA testing has come a long way since it was first used in the 1980s. Today, it's not just about crime dramas or lab experiments — it's a practical tool you can use to learn more about your family, your health, and even your legal rights. Whether you're curious about an ancestry DNA test, confirming paternity, or checking sibling relationships, there are plenty of options out there.

In this guide, we’ll break down how DNA tests work, how accurate they are, how much they cost, and what you can find out — even during pregnancy.

What Is a DNA Test and How Does It Work?

DNA (deoxyribonucleic acid) is the genetic blueprint of who we are. A DNA test compares specific parts of your genetic code to someone else’s to see how closely you're related.

Most DNA tests are quick and painless — often just a simple cheek swab. Lab specialists then compare the DNA samples to check for matching markers.

Why Might You Need a DNA Test?

People get DNA tests for all sorts of reasons, including:

  • Paternity testing – to confirm the biological father of a child
  • Sibling DNA tests – to find out if two people share one or both parents
  • Prenatal testing – to determine paternity before the baby is born
  • Ancestry testing – to discover your heritage and family history
  • Medical reasons, such as checking for inherited conditions

You can explore our private DNA testing services to see what might suit your situation.

When Did DNA Testing Start?

DNA testing first emerged in 1984, when Sir Alec Jeffreys developed DNA profiling at the University of Leicester. Since then, technology has evolved dramatically, making testing faster, more accurate, and more accessible to the general public.

Types of DNA Tests Available

1. DNA Test Paternity Test

A paternity test helps confirm if someone is the biological father of a child. It’s commonly used for legal cases, child support, or peace of mind. These can be done:

  • After birth – using cheek swabs
  • Before birth – via noninvasive prenatal paternity tests

2. Can You Do a DNA Test Before Birth?

Yes! You can do a DNA test before birth, starting from the 8th week of pregnancy. Options include:

  • Noninvasive prenatal paternity test (NIPP) – using the mother’s blood
  • Amniocentesis – taking a sample of amniotic fluid (has small risks)
  • Chorionic villus sampling (CVS) – testing placenta tissue (also carries slight risks)

3. Sibling DNA Test

A sibling DNA test checks if individuals share one or both biological parents. These tests can be helpful in adoption cases, family reunions, or when a parent is unavailable for testing.

How Can You Do a DNA Test?

Wondering how we can do a DNA test? It's easier than ever:

  • At-home kits: You swab your cheek, post the sample to a lab, and wait for results
  • Clinical testing: More accurate and legally valid – ideal if needed for court or medical records
  • Prenatal testing: Requires a blood draw or a specialised procedure

At Private Medical Clinic, we offer fully accredited laboratory testing for both legal and private DNA purposes.

How Much Does a DNA Test Cost?

How Much Is a DNA Test in the UK?

  • At-home kits: £15–£200 (plus lab and postage fees)
  • Clinic-based tests: £300–£500
  • Prenatal tests: These are more advanced and may cost more depending on the procedure

Note: DNA testing isn’t usually covered by the NHS or private insurance unless it's medically necessary.

How Accurate Is a DNA Test?

DNA testing is highly accurate. Paternity tests are typically 99.9% accurate. However, errors can happen if the samples are contaminated or the lab isn’t accredited, which brings us to an important question…

Can a DNA Paternity Test Be Wrong?

While rare, DNA paternity test results can be wrong if:

  • The wrong person was tested
  • Samples were contaminated
  • A low-quality test was used
  • The lab lacked proper certification

Always choose a lab that’s accredited by organisations like the AABB (American Association of Blood Banks).

Need help booking a test with a trusted provider? Book an appointment with us today.

What Can a DNA Test Tell You About Your Ancestry?

An ancestry DNA test can reveal:

  • Your ethnic origins and geographic roots
  • Migration patterns of your ancestors
  • Potential relatives and family matches

Some tests even estimate how much of your DNA is linked to different global populations — from African heritage to Scandinavian roots.

How to Spot a Fake DNA Test Result

Sadly, not all DNA tests are legitimate. Here's how to spot a fake DNA test result:

  • No clear accreditation or lab certification
  • Vague or overly simplified results
  • No contact information or support from the testing provider
  • Wild or inconsistent ancestry claims

Choose a trusted clinic like ours for accurate and professional testing.

FAQs About Ancestry DNA Test

How accurate is an ancestry DNA test?

Most are 95–99% accurate, depending on the database size and genetic markers analysed. Always choose a test from a reputable lab.

Can an ancestry DNA test tell me who my relatives are?

Yes – they can connect you with relatives who’ve taken the same test, helping build your family tree.

Can ancestry DNA tests be used for legal purposes?

No. These tests are not court-admissible. For legal matters, use a certified paternity or relationship test.

Are ancestry DNA tests safe during pregnancy?

Yes – but they’re different from paternity tests. You can safely do an ancestry test after birth, or use a noninvasive prenatal test to check paternity.

Final Thoughts

Whether you're exploring your roots with an ancestry DNA test, confirming family ties, or planning for your child’s future, DNA testing offers clarity, peace of mind, and sometimes even life-changing answers. From pregnancy to adulthood, there’s a test to suit your needs.

At Private Medical Clinic, we offer confidential, reliable DNA testing services with full support from start to finish. If you're unsure where to start, speak to our team today — we're here to help.

Latest blog posts

Doctor holding a card with text HEPATITIS A
Health

Hepatitis A: Symptoms, Causes, Transmission and Prevention

Hepatitis A is a short-term but highly contagious liver infection. It’s not very common in the UK, but if you’re travelling abroad or in close contact with someone who has it, it’s important to understand how it spreads.
Front view woman dealing with genital warts
Sexual Health

Genital Warts Explained: Symptoms, Causes and Treatment Options

Genital warts are one of the most common types of sexually transmitted infections (STIs), but they can still feel a bit awkward to talk about. That’s why we’re here to explain exactly what they are, how they spread.
Top view women reproductive system and pills
Sexual Health

Chlamydia Treatment Guide: Symptoms, Testing and Antibiotics

Chlamydia is one of the most common sexually transmitted infections (STIs) in the UK. A type of bacteria causes it and often spreads through unprotected vaginal, anal, or oral sex.
young woman coughing with fist
Health

Asthma Guidelines UK: BTS, NICE & SIGN Unite on Diagnosis and Management Standards

Asthma affects over 5 million people across the UK. Whether you're living with asthma, treating patients, or simply want to stay updated.
Man Using Inhaler for Respiratory Health
Health

Adult Asthma Explained: Symptoms, Silent Attacks, Causes, Testing, and Late-Onset Diagnosis

Asthma isn’t just a childhood condition. Adult asthma is more common than most people realise. It can develop out of the blue and, if not managed properly, can be life-threatening.
Mother treats her daughter at home
Health

Childhood Asthma Symptoms: How to Test, Diagnose and Spot Flare-Up Signs in Kids

As a parent, spotting the early signs of asthma in your little one can feel daunting. In this post, we’ll guide you through the most common childhood asthma symptoms and outline how to diagnose asthma in a child.