Our Sibling DNA Test can verify a biological relationship between a child and their full sibling or half sibling, giving you the answers and peace of mind you need. We often run this test when the possible father isn’t available for testing, since results between two potential siblings can help establish paternity indirectly. Including a common mother in testing increases the probability of paternity once a relationship is confirmed. We can also use a sibling DNA test to confirm a potential relationship found through ancestry testing. If you’re not sure whether someone is your biological brother or sister, order a test with us to find out.
Sibling DNA Testing for Personal and Legal Use
A sibling DNA test can confirm whether you and someone else are biologically related, whether the possible father isn’t available for testing, or you simply want answers.
Discreet
Convenient
Over 99.99% Accurate
Affordable
DNA Testing Options For Siblingship
DDC offers two different types of sibling DNA tests: legal tests and at-home tests.
Legal DNA Tests
This test offers court-admissible results. To maintain proper chain of custody, all tested parties must have their DNA samples collected at a certified facility, such as one of ours, a hospital, medical office, or health department. The sample collector also verifies the identity of every tested party through a government ID or other legal documentation.
At-Home DNA Tests
This test does not offer court-admissible results. If you want a sibling DNA test purely for personal peace of mind, an at-home test may be the better fit. At-home relationship testing is just as accurate: our lab follows the same strict process that legal tests require, the only difference is that sample collection happens at home, unwitnessed.
DNA Testing With Reputable Accreditations
Accreditations apply to legal DNA tests under scope.
Reliable Sibling DNA Testing Through DDC
When you choose to work with a world leader like DDC for your sibling DNA testing needs, you can rely on the results. Our US-based laboratory holds the highest level of accreditations available, including AABB, CAP, and CLIA certifications.
Results in 5 Business Days
Once all samples arrive at the lab.
PhD-Reviewed Results
Our in-house experts ensure accuracy.
Team Support
Stay informed every step of the way.
Over 30 Years of Experience in DNA Relationship Testing
AABB-Accredited
First and only test accredited by the Association for the Advancement of Blood & Biotherapies.
American Pregnancy Association
The only test endorsed by the American Pregnancy Association.
30 Years
Over 30 years of experience in DNA relationship testing.
How the Sibling Test Process Works
We make the sibling DNA testing process easy by offering flexible options that meet your needs. Our customer support representatives are available to help you every step of the way.
Give Us a Call
Call our experts for a free, no-obligation consultation to get started. We’ll help you navigate your situation and determine whether a legal or at-home test is right for you.
Collect the DNA Sample(s)
If you opt for an at-home sibling DNA test, we’ll send a complete kit right to your doorstep in discreet packaging. Simply collect cheek swabs (or other allowable sample types) from both tested parties, and return the samples in the prepaid mailer.
If you order a legal sibling DNA test, both tested parties can easily provide their DNA sample in-person at one of our 5000+ collection locations worldwide. Multiple appointments can be set up in different locations if necessary.
Your Test is Carefully Processed
Our lab technicians carefully handle and prepare your samples for processing. Every relationship test that uses a buccal (cheek) swab is run twice, by two independent teams, and reviewed by our in-house PhDs before your report is prepared.
Receive Your Results Online
Once the sibling DNA testing process is complete, we’ll send you an email that will allow you to log in to our secure website and view your results. Your test results are completely confidential, and your private genetic information is never shared with or sold to outside parties. See our privacy policy here.
We Are Your Sibling DNA Experts
Sibling DNA testing carries more nuance than a standard paternity test. Results can show a full sibling relationship, a half sibling relationship, or no biological relationship at all, and including a shared mother in testing raises the probability of a conclusive result. We run every sibling DNA test in our own accredited lab, and our in-house team has spent over 30 years working through cases like these. We perform thousands of relationship tests each year, including:
FAQs About Sibling DNA Tests
Here are some of the questions we hear most often about sibling DNA testing.
How does this test work if it’s unknown whether the potential sibling is a full or half-sibling?
If it's unknown whether a potential sibling is a full or half sibling, we first test to see if there's any biological relationship at all. If there isn't, testing ends there. If a relationship is confirmed, we can run a full sibling test at your request.
Can a sibling DNA test be used to confirm a possible relationship discovered through ancestry testing?
Yes. A sibling DNA test can confirm a possible relationship discovered through ancestry testing. We analyze specific DNA regions inherited from each person's parents, compare genetic similarities, and calculate an accurate probability of relationship.
How accurate is a sibling DNA test compared to a paternity test?
A sibling DNA test is just as accurate as a paternity test, though the conclusiveness of results can vary more. A father-child relationship is almost always 99.9% or higher, or 0% if he's not the father. For a sibling DNA test, the probability might land at 91%, which is still a conclusive result. Including a shared mother in testing increases the probability of paternity when siblingship is confirmed.
Can a DNA test for siblings be used for legal reasons?
Yes, as long as a chain-of-custody procedure is set up and followed. Results from a legal sibling DNA test are court admissible and can be used for legal reasons such as Social Security, inheritance rights, immigration, or custody. Results from an at-home sibling DNA test kit cannot be used in court.
How much does a sibling DNA test cost?
Sibling DNA testing costs vary based on whether you need results for personal knowledge or for court, how many parties are tested, and whether a mother is included. Call our DNA advisors for a free consultation and quote.
How do I understand results for a sibling DNA test?
Your sibling DNA test results report gives the probability of relationship (PRI) as a percentage. Here's how to interpret it:
- 90.9% or higher means the sibling relationship is supported by DNA testing
- 9.09% to 90.9% is an inconclusive result, meaning additional parties need to be tested
- Below 9.09% means the sibling relationship is not supported by DNA testing
For example, a PRI of 93% means there's a 93% probability that the people tested share a full sibling relationship.
Does including a shared mother increase the probability of a sibling-based paternity test?
Yes. If your goal is to confirm a common father with a possible sibling, including a shared mother is the best option. When we test two potential siblings along with their mother, the probability of paternity is likely higher once siblingship is confirmed.
Full Sibling or Half Sibling?
Full siblings share both biological parents; half siblings share only one. A sibling DNA test can tell you which relationship applies, or rule out a biological connection entirely. Because siblings inherit different combinations of DNA from their parents, results can be less absolute than a parent-child test: a probability of relationship in the 90s is still considered conclusive, even though it isn't the near-100% or 0% you'd see in a paternity test. Testing a common mother alongside both possible siblings raises that probability further.
DNA Diagnostics Center Reviews
Give Us a Call
Call our relationship testing experts today for your free, confidential consultation!
