Zygosity Twin Testing


  •  Just £149 for next day results, or upgrade to same day results for an extra £70
  • The UK’s fastest DNA twin test. Why wait?
  • Award-winning UK accredited laboratory
  • Trusted to provide DNA testing to The Jeremy Kyle Show, This Morning and Family Finders

Our non-invasive DNA twin test can quickly determine whether multiple children are identical or not

£219 Same day results

To receive your results the same working day click here.

£149 Next day results

To receive your results the next working day click here.

Four easy steps for your DNA zygosity test

Buy your collection kit


Collect your cheek cell DNA samples


Post back to our laboratory


Receive your results by email


Zygosity twin testing

Zygosity twin testing is used to determine whether multiple children from the same birth (twins, triplets, quadruplets, etc.) are genetically identical or not. If siblings are identical, they are known as monozygotic. This means that they were formed from a single fertilised egg, which went on to split into separate embryos. It also means that their DNA is exactly the same.

Non-identical siblings from the same birth are known as dizygotic (i.e., having two zygotes). Triplets are trizygotic (three zygotes), quadruplets are quadzygotic (four zygotes), and polyzygotic is the umbrella term for multiple zygotes. This means that these siblings are the result of separate fertilised eggs and that they share DNA in common (as in the case of siblings from different births).

Why would you need a zygosity twin test?

Siblings that are of different sexes are non-identical. Twins of the same sex can start to have different physical features as they grow. Growth patterns (such as hair and eye colour, ear shape, teeth formation, hand and feet appearance) can indicate whether or not the children are identical. By around 2-years-old, their zygosity may be quite clear from their physical features.

Reasons why zygosity twin determination would be required:

It can be interesting to know whether multiple siblings are identical.

It may have been unclear in utero. Identical twins don’t always share the same placenta and sac: it all depends on when the eggs splits.

Parents obviously want to know this information, and sometimes the twins themselves like to know when they’re older.

It can help reinforce the need to treat the siblings as individuals.

It can be useful to know whether multiple siblings are identical.

It can help assess the likelihood of conceiving twins again: there is an increased risk for women who have had non-identical twins.

Some illnesses may affect monozygotic children so you would know whether both/all children need testing for a particular condition.

You may need this information to participate in any research about multiple births.

In addition, some people buy DNA zygosity profiles as a unique gift idea for multiple birth parents or their children.

What does the twin test entail?

Our UK-based laboratory uses the most up-to-date DNA testing technology to ensure the reliability and accuracy of our genetic testing. We were the first UK laboratory to offer accredited 24-marker DNA testing and retest all our exclusion results.

We send your DNA test kit direct to an address of your choice using discreet packaging.

The test kit includes mouth swabs to obtain tiny amounts of DNA from inside each sibling’s mouth. The swab is rubbed gently and painlessly on the inside of the cheek, so it is not a problem if anyone involved is scared of needles.

When we receive your sample in our laboratory we examine specific markers present in repeat sections of DNA from each sibling. These 24 Short Tandem Repeat (STR) loci include the Amelogenin (gender) locus. The DNA seen at each of these STR loci is compared between the tested individuals and zygosity is determined; monozygotic twins will share the same DNA profile whereas dizygotic twins will have different DNA profiles. A DNA profile is produced for each of the samples provided.

DNA zygosity test support service

How to take a DNA zygosity test

We recommend that you watch the video above where clinical psychologist Lisa Marsland talks about the issues that may arise from taking a DNA zygosity test.
Learn how to take your DNA samples at home using one of our test kits from the comprehensive video above.

What’s in our DNA twin testing kit?

Our DNA twin testing kit contains enough collection swabs to test two siblings. Extra swabs can be added for extra siblings as required.
Our home twin test kit is designed to be user-friendly with easy-to-understand instructions on how to take your test samples and return them back to our UK-based laboratory.
If you have any questions or do not understand how to take your samples please get in touch on: 0333 600 1300 as we are more than happy to talk you through the process.

Order a DNA zygosity twin test today and you will receive:

  • Peace of Mind DNA zygosity test request/consent form
  • Full instructions on how to take the DNA twin test and return the samples back to us
  • A self-addressed envelope to send your DNA samples back to us
  • Two DNA sample collection swab packages containing two swabs in each package
  • Individual DNA test sample envelopes for two siblings

If you want to test more than one sibling with the same test, you can add extra siblings to the package when ordering and more swabs will also be provided in the test kit.

The Queen Awarded Paternity DNA Testing

For 26 years we believed that our twin boys were non-identical, as confirmed by the gynaecologist during the scan, which showed that they were in two separate sacs and that there were two placenta present.

All through their lives people struggled to tell the boys apart and we decided to arrange a zygosity test with AlphaBiolabs to clarify the matter once and for all.

To our surprise the results confirmed that the boys are identical. This has ended years of speculation within the family and has provided us with conclusive scientific proof.

Gail and Chris Evans

Buy your zygosity testing kit here today