Sibling DNA Testing
ReliaLab Test provides sibling DNA testing to determine whether two people share one or both biological parents, including full sibling, half sibling, and twin zygosity testing. Testing is available nationwide through a network of more than 15,000 collection clinics, with local service from ReliaLab's team based in Nashville, Tennessee.
How Sibling Testing Works
Cheek swab samples are collected from both individuals being compared. The lab analyzes shared genetic markers to estimate the likelihood of a full sibling, half sibling, or no biological relationship. Including a parent's sample, when available, improves accuracy.
Which Type of Sibling Test Do You Need?
Legal Sibling Test
Every participant's identity is verified with photo ID, and collection is witnessed by a neutral, trained collector at a collection clinic or by a mobile collector. Choose this when the result may be reviewed by a court or used for legal purposes.
Order a legal test → Home KitInformational (Home) Sibling Test
A kit is mailed to your home. Participants self-collect a cheek swab and mail it back to the lab. There is no witnessed collection, so this is for personal knowledge only.
Order a home test →How Legal Sibling Testing Works
1
Order Online
Complete the intake form below and receive your Test Authorization Order by email.
2
Visit a Collection Clinic
Bring the Authorization Order and photo ID to a nearby clinic from the 15,000+ location network.
3
Sample Collection
A trained collector verifies identity and collects a cheek swab from each participant.
4
Receive Results
Results are emailed securely, typically within 3 business days.
Order a Legal Sibling Test
Court-admissible, with a documented chain of custody.
Sibling Testing FAQ
Yes. The lab analyzes shared genetic markers to estimate the likelihood of a full sibling relationship, a half sibling relationship, or no biological relationship.
Yes, twin zygosity testing compares DNA between twins to determine whether they are identical (from one fertilized egg) or fraternal (from two).
Yes. When available, a shared parent's sample significantly improves the accuracy and confidence of a sibling test result.
A legal test has a witnessed collection with photo ID verification and a documented chain of custody, making it admissible in court. A home test is self-collected and is for personal knowledge only.
No. While ReliaLab Test is based in Nashville, Tennessee, sibling testing is available nationwide through its 15,000+ collection clinic network or a mailed home kit.
Looking for a Different Kind of Relationship Test?
Explore every DNA testing option ReliaLab offers, all available nationwide with local service from Nashville, TN.
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