Sibling DNA Test-Testing Brother or Sister Relationships

Sibling DNA Testing is a DNA test process that is performed to determine if two or more people share one or both parents. For example to determine if they are full or half siblings. Sibling DNA tests are typically used as an indirect method to prove family relationships when the alleged father is not able to perform a paternity test. However, in rare cases, sibling tests are used to determine if 2 people share the same mother.

With all relationship testing, the mother of the child is always urged to test. This allows less of a chance to receive inconclusive results. If the biological mother is not available, the test can still be performed. Additional undisputed siblings can also be added to provide a stronger test result. To discuss the best options, give us a call to help you decide what is best.

How Sibling DNA Testing Works

Order Sibling DNA Test

After deciding on a test, we will either send out a Home Sibling DNA Test Kit or schedule an appointment for Sibling DNA Testing at any of our 1000+ Testing Centers for DNA collection.

Collect Samples

DNA collection is painless and easy to perform. DNA collections are performed with non-invasive buccal swabs. The swabs are brushed lightly on the inside of each individual’s cheeks for around 10 seconds.

Get Sibling DNA Results

Results typically complete within 3-10 days after the laboratory receives all testing kits. Sibling test results are then provided over the phone and email. Mailed copies can be sent upon request.

Full Sibling vs Half Sibling DNA Testing

When two siblings share the same mother and want to learn if they share the same biological father a full sibling DNA test would be performed. If the test confirms the biological father of the siblings they would be full siblings.
The full sibling test can only be used if two siblings share the same mother.

Half Sibling vs Not Related DNA Testing

When two siblings do not share the same biological mother but want to learn if they share the same biological father.

The half sibling test can be performed with or without the mothers involved. Adding a mother to testing is always encouraged for more conclusive and accurate results.

Legal Sibling DNA Test vs Sibling DNA Test Kit

Test Me DNA can provide you with Court Admissible or Peace of Mind results for siblingship testing. Whether your specific situation requires you to choose the Legal Documentation or you are just doing this test for personal knowledge, rest assured that our AABB accredited lab will process all siblingship tests exactly the same. There is absolutely no change in the accuracy or precision of the final results. The only difference comes in the Notarized results, along with a Chain of Custody that is provided with the legal siblingship test.

Sibling DNA Testing Kit

  • Discreet shipping, free shipping both ways

  • Easy to use kit with detailed instructions

  • Fast results: 3-10 business days after returning the kit

  • Results are private and confidential

  • One low price includes kit & results

  • 99.9% accurate results to ease your mind


Order the Sibling Home DNA Testing Kit today. The easy to use form will get the paternity testing process started.

Orders submitted by 2PM CST Monday-Friday will be shipped the same day you order

Legal Sibling DNA Testing

  • Same Day Appointments in most areas

  • Painless DNA collection

  • Fast results: 3-10 business days

  • Results are private and confidential

  • One low price includes testing & legal DNA results

  • 99.9% accurate results that will hold up in court


Call to order a Legal DNA Sibling Test. In a simple phone call, our DNA specialists will walk you through how the DNA testing works and get you scheduled.

Appointments are Monday-Friday, and can usually be scheduled for the same day.


A sibling paternity test is when 1 person is trying to determine their paternity by testing with a possible sibling. 1 or more known children to the father would be tested against the unknown child to the father. The sibling paternity testing would compare the people testing to see if they share the same father.

If a father or alleged father is not willing or not available to test, a sibling DNA test is a great option.

Children receive a half of their DNA from each parent. When testing samples from a sibling test, the lab looks at the genetic markers to reconstruct parts that came from the parent at question. Testing the mother helps with the reconstruction, because if you include the mother, you can see exactly what part of the DNA came from the father.

The most common reasons to do a legal sibling DNA test would be because the father is deceased and unable to test.

Sibling DNA testing for social security survivor benefits, can be used if the child at question is a minor. If the child at question is not a minor, then it is commonly used for inheritance purposes or probate court.

Yes! Home DNA testing kits are available for all of our relationship DNA tests.

If the test results are only needed for personal testing, then a sibling home DNA kit is a great option!

For most sibling tests, the samples are collected using sterile buccal swabs. These sterile cotton tip swabs are rubbed on the inside of the cheek collecting the epithelial cells. Buccal swab collections are completely painless and can be used on adults, children as well as babies. Due to the fact that the DNA found in our cheek cells is the same DNA found in all of our cells in our body, the results from this test would be exactly the same as if performing the test using a blood sample or other “special” samples.

Legal sibling tests must be collected at one of our many collection sites. This allows the collection to be taken by a professional neutral third party. They will also take a thumbprint and a photo at the time of collection, providing proof of who was collected.

A minimum of 2 people need to be tested for a sibling DNA test. But some sibling tests may need additional siblings to be included to get a definitive answer. This all depends on how the DNA was passed from the parents to the children. Parents will not always pass the same alleles to each of their children.

The price of a sibling test is dependent on a few factors. How many people are testing? Do you need the test for legal purposes or just personal knowledge?

The cost of a legal sibling DNA test including 2 possible siblings is $349. Any additional person is $125.

The cost of a home sibling DNA test including 2 possible siblings is $179. Any additional person is $69.

If the child at question is a male, it is always best to do a DNA test with a brother or possible brother. If the 2 brothers are doing DNA testing to determine paternity, there are Y chromosomes that would be an exact match down the male lineage.

If the child at question is a female, DNA testing with a sister or a brother would hold the same level of accuracy.

Sibling DNA test results provided by our AABB and ISO 17025 accredited laboratory are deemed, useable for life. These accreditations confirm that the highest possible standards and competence is being upheld by the laboratory. US government agencies, or state institutions require that your sibling DNA test be preformed by a laboratory with an AABB accreditation. Courts throughout the United States regard our legal sibling DNA results as absolute proof of the relationship in question.
The AABB standards maintains that a legal sibling DNA test must have a strict chain of custody to be valid in any legal matter and admissible in court. An unbiased medical professional must perform the sample collection, and willing participants must provide legal identification as well as sign acknowledgement of their consent. As part of the procedure, those signatures of consent, fingerprint and photo of the participants, and any other identifying information will be provided on the chain of custody.
Our sibling DNA testing laboratory trains all technicians to follow these procedures to ensure that results may be used for any legal matter. Our testing laboratory is composed by experienced PhD geneticists who administer the testing process in accordance to the AABB and ISO accreditation standards. This ensures that the most up to date testing methods and technology are being used to complete your sibling DNA test.

Learn More

Full siblings will not exhibit a complete DNA match, unlike identical twins, who share identical DNA profiles. Each individual inherits half of their DNA from their mother and the other half from their father. However, the specific DNA passed down by parents to their children can vary among siblings.