DNA Testing FAQs

If you are unable to find the answers to your questions below our Customer Services team are here to provide help and assistance - call us (free) on 0800 036 2522. Our lines are open 8.00am to 6.00pm Monday - Friday.

DNA paternity testing is a complex scientific process, carried out on a simple mouth swab, which can positively identify relationships between people. Most commonly it is used to establish if a man is the true biological father of a child.

DNA paternity testing is also often referred to simply as a DNA test, a paternity test or DNA testing. It was developed by Sir Alec Jeffreys at the University of Leicester in 1985. Cellmark became the UK's first private DNA paternity testing laboratory in 1987.

DNA (Deoxyribonucleic Acid) is the body's genetic 'blueprint'. It is a long thread-like molecule which carries the "genetic code" that determines our individual characteristics. DNA is found in almost all of the billions of cells that make up our body. Every child inherits a unique mixture of DNA from its parents so, except for identical twins, no two people in the world have exactly the same genetic code.

It works by detecting certain parts, or 'markers' in the DNA molecule that are known to vary greatly between unrelated people. Our tests compare the DNA at a number of these markers to determine if people are related.

The process is called Short Tandem Repeat (STR) profiling. STR profiling is a very sensitive DNA testing procedure that was originally developed for forensic analysis. DNA is extracted from the sample and a special enzyme is used to copy the genetic code at the relevant regions in the DNA. At Cellmark an STR profile in a relationship testing case is the result of a minimum of 22 separate DNA tests.

Cellmark delivers a next working day DNA Relationship testing service - as standard - across our range of tests - including immigration and sibling cases. If your samples reach us by 10am we can get the test report to you by the end of the next working day!

Completing our online registration form will only take a few minutes, however you will still need to make an appointment to have your DNA sample taken.

When a mother, child and possible father are tested Cellmark's results will either show he is not the father or normally provide proof of paternity with a confidence level of at least 99.99% and usually greater than 99.9999%. Including a sample from the child’s mother is always recommended to ensure the most conclusive result.

Yes, under the requirements of UK Data Protection laws, the service and results are confidential. Everyone who gives a sample or has Parental Responsibility for the child on the case is entitled to request a copy of the results. Results are not passed on to any third parties unless you request us to do so. In order to further protect confidentiality we do not discuss results of tests over the telephone.

You will need to make an appointment have your samples taken by a Doctor or a Nurse or a Cellmark trained sampler. At that appointment a mouth swab will be rubbed gently and painlessly on the inside of your mouth to collect a sample of cheek cells.

You will also need to complete a consent form at the surgery (please remember to take 2 passport style photographs of each person being tested to the appointment) and these and the sample will then sent to Cellmark by the surgery. If you elect to use Cellmark's mobile sampling service (they will come to you and an extra fee will apply) our samplers will take photographs of the individuals to be tested at the sampling appointment.

When carrying out a paternity test the DNA of the mother, the child and the possible father are compared using DNA markers called STRs (please see ‘How does DNA testing work‘ for more information).

Each STR marker identifies up to two ‘results’ in each person’s DNA, one inherited from their mother, and one from their father.  If the same sized STR result is inherited from both parents, the individual appears to have only one result for that STR test.  We carry out 24 tests in each case and each person’s DNA profile is made up of the results from a minimum of 22 separate STR tests.

To carry out a paternity test we examine all the STR results in the child’s DNA profile and check that they are all matched by results in the mother’s and the father’s DNA profiles.

If the mother is not tested, we can still compare the child’s profile with the DNA profile of the alleged father to see if there is a matching result for every test, but without the mother’s DNA we have to make some assumptions in the analysis which reduce the statistical certainty of the conclusion.   

Two passport sized photographs and/or photographic ID of each person being tested must be presented at the sampling appointment. These will be used to confirm the identity of the person(s) being tested and will be sent with the samples to Cellmark. If you elect to use Cellmark's mobile sampling service (an extra fee will apply) our samplers will take photographs of the individuals to be tested at the sampling appointment.

In paternity cases all identification paperwork is held by Cellmark for a period of 1 year after which time the paperwork is destroyed in compliance with our registration with the Data Protection Act.

The use of mouth swabs means that testing can be performed on a child of any age after birth. Some companies may offer pre-natal DNA testing but Cellmark agrees with the Human Genetics commission's view that knowing the identity of the genetic father of the foetus could significantly influence the decision whether or not to proceed with a pregnancy and therefore Cellmark does not offer pre-natal DNA testing.

Cellmark is a UKAS accredited testing laboratory No. 2045. Our quality management system has met ISO standards since 1990 and our laboratory procedures are accredited to ISO9001, ISO17025 and ISO27001 and are subject to external monitoring. We are accredited by the Ministry of Justice as a body that may carry out parentage tests (otherwise called DNA Testing or Paternity Testing) as directed by the civil courts in England and Wales under section 20 of the Family Law Reform Act 1969 and we also adhere to the Human Genetics Commissions "Common Framework of Principles on DNA testing".

DNA testing can be used to assess a range of relationships such as maternity, siblings (brothers and sisters), aunt/uncle or grand-parentage, either to confirm that particular relationship, or in some cases to determine a child’s parentage when the parents of the child aren’t available for testing.  For more information on how Cellmark’s DNA testing service might be able to assist you, please contact our Customer Services team on 0800 036 2522.

The samples are sent to our laboratories in specially designed tamper-evident packaging. Once testing is complete and you have received the results, your DNA sample is stored securely for 3 months after which time it is destroyed.

In paternity cases all identification paperwork is held by Cellmark for a period of 1 year after testing is complete after which time it is destroyed in compliance with the Data Protection Act 1998.

As directed by Data Protection laws your information will not be passed onto anyone you have not given us authorisation to do so. For further information please refer to our privacy policy. You can also learn more about the Act by on the Government's website.

We do not give out or discuss results over the telephone, however we are pleased to answer written enquiries about your specific results and to talk through general issues relating to DNA paternity testing. Call our Customer Services team.

If you require further information, or your question isn't listed here, then please call one of our friendly, professional and confidential Customer Service advisors on 0800 036 2522, or send your question via email to info@cellmark.co.uk, or use our discrete SMS service.

Following the reduction in legal aid funding the Legal Aid Agency has produced a range of information to assist solicitors and individuals in establishing whether their case is eligible for Legal Aid funding and this can be accessed via the following web page - https://legal-aid-checker.justice.gov.uk/ we recommend you use this as a starting point before embarking on the complex process of applying for legal aid.

If you can’t get Legal Aid you may be able to get free advice from one of the following:
The Law Centres network
Citizens Advice

You can also pay for advice from a local legal advisor or solicitor – a number of firms are responding to the changes by offering fixed price services.

Links to Cellmark’s standard Terms and Conditions can be found in our website footer.

To order a DNA relationship test you need to be at least 18 years old.