Sibling DNA Testing

For a sibling DNA test, cheek swabs are used to collect DNA samples from each sibling and the biological mother, if available.

Once these samples arrive at the laboratory, our in-house geneticists analyse and compare the DNA samples to determine the genetic profile of the possible siblings and calculate a sibling DNA index or likelihood ratio.

• A likelihood of greater than 10 supports that the tested individuals are either full or half siblings
• A likelihood of less than 0.1 is not supportive, meaning the individuals are unlikely to be related
• A likelihood which falls between 0.1 and 10 is considered inconclusive, which means a relationship cannot be determined based on the statistical probability obtained from the analysis

Our Sibling DNA test results are 100% accurate and reliable based on the samples we receive at our laboratory.

We are also accredited to the international quality standard ISO 17025 for our DNA testing. 

Yes, the Sibling DNA test can be used to determine whether individuals are half siblings.

Half siblings share one biological parent – the mother or father – and will normally share more DNA than people who are not related.

This makes it possible to use sibling DNA testing to determine whether individuals are:

• more likely to share one common parent (i.e. they are half siblings, with one biological parent in common) or
• are more likely to be unrelated

A sibling DNA test requires cheek cell DNA to be collected from each sibling, using cheek swabs.

We also ask that the biological mother’s DNA sample be provided where possible, for the most conclusive result. However, we can still perform the test without the mother’s sample.

Your DNA test kit will contain enough cheek swabs to collect DNA samples from two siblings and the biological mother (if available), along with full instructions on how to collect your cheek cell DNA samples and return them to our laboratory.

You can also choose to add a third sibling to the test for an additional €60, and more cheek swabs will be provided in the test kit.

For the most conclusive result, we do ask that the biological mother also provides a cheek swab sample, if possible.

However, this is not essential, and we can still perform a sibling DNA test without the mother’s sample.

Your test kit will contain enough cheek swabs to collect DNA from two siblings and the biological mother (if available).

Yes, you can choose to send a test kit to a second address, for an additional fee.

Simply choose this option when placing your order.

You will receive your results in just 2-3 days after your samples have arrived at our laboratory. 

You can order an AlphaBiolabs Sibling DNA test for €189.

This includes DNA testing for two siblings and the biological mother. You can choose to add a third sibling to the test for an additional €60.

You can order your Sibling DNA test here for just €189.

Your test kit will be shipped out to you immediately in discreet, plain packaging.

Need advice on whether this test is right for you? Call our friendly and knowledgeable Customer Services team on 01 402 9466 or email info@alphabiolabs.ie.

Our Sibling DNA testing kit includes full instructions on how to collect your cheek swab samples, DNA swab packages, swab envelopes, individual DNA test sample envelopes, and a self-addressed envelope to send your test samples back to us.

Your test kit will be sent out in discreet, plain packaging for full confidentiality.