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Sibling Test

Do brothers and/or sister share the same parents

Sibling DNA Test Kit Product Image
Sibling DNA Test Kit Product Image

In the kit

The DNA testing kit contains everything you need to take your DNA samples and return them to us for testing. 

  1. A folder with information about Cellmark and the DNA testing kit
  2. Clear instructions about how to take the DNA samples
  3. A mouth swab for each person to be tested
  4. A sample collection card for each person to be tested
  5. A sample declaration form for each person, requiring a signature to provide consent
  6. A tamperproof, prepaid return envelope

All our Home DNA kits are mailed out inside a non-branded envelope, there is no mention of Cellmark or DNA at Home on the envelope and it will be labelled ‘Private and Confidential’.

Next Day results

If all of your DNA samples arrive at our UK laboratory before 10am we aim to send the test result to you by the end of the next working day by email.

Important Information

Siblings are brothers and/or sisters. Full-siblings have the same mother and father, while half-siblings share only one parent. A sibling test can be used to confirm whether two, or more children are related and to identify if they share one or both biological parents.

Sibling analysis is not as conclusive as paternity testing and can only report the most likely relationship ‘given the DNA evidence’.

The results will provide a statistical likelihood of whether two individuals are true biological relatives but DNA testing for this type of relationship cannot provide a conclusive result. Because of the patterns of DNA inheritance it is not always possible to detect a half sibling relationship or to differentiate between a half or full sibling and so it may not always reveal the true nature of the relationship, or provide strong evidence.

However, this type of DNA analysis is the best way to investigate a sibling relationship and if either of the parents of the siblings are available for testing, this will aid the analysis and may increase the certainty of the result.

Please note that DNA at Home's sibling test is for ‘curiosity’ purposes only; if the results are going to be used in a legal matter they may not be accepted by the UK courts and we would encourage you to visit our legal DNA testing site to order a test -

As with all our DNA relationship testing services we offer a Next Day DNA service at no extra cost.  This means that if all the DNA samples for your test arrive at our UK laboratory before 10am, we aim to send the test result to you by the end of the next working day by email (also please see our FAQs).

DNA relationship testing can be a life changing event and we would urge that before ordering a test you think carefully about the potential outcomes.

If you have any questions please call our customer services team free on 0800 043 1987.