DNA Sibling Test
- Results in 1-2 business days
- Easy at-home sample collection
- 2x Testing Guarantee
- AABB, ISO/IEC 17025 & CAP-CLIA Accredited
- Serving Families Across [the_region]
DNA Sibling Testing
Establish biological relationships between potential siblings with scientific precision. Our DNA Sibling Test compares DNA profiles to determine the likelihood of full sibling relationships (sharing both biological parents), half sibling relationships (sharing one biological parent), or no sibling relationship. This test is especially useful when one or both biological parents are unavailable for testing, making it a practical option for families seeking clarity about their genetic connections.
How it Works
Order your DNA Kit
Place your order online, and we’ll send you a DNA test kit with everything you need to collect your samples.
Collect your Samples
Follow the detailed, step-by-step instructions to collect DNA samples using the provided mouth swabs.
Lab Analysis
Use the provided return envelope to mail your DNA samples to our accredited laboratory for analysis.
Receive Results
Download your DNA results from your online account within 1-2 business days of sample receipt at the lab.
How Our DNA Sibling Test Provides Answers
DNA Tests Direct is committed to providing accurate and private DNA testing services for families across the United States.
- Accredited Laboratory: Our testing laboratory holds major international accreditations, including AABB, CAP, and CLIA, ensuring your test is performed to the highest global standards.
- Fast & Confidential Online Results: Receive your confidential results through a secure online portal within 1-2 business days from the moment our laboratory receives your samples.
- Comprehensive Analysis: Our laboratory analyzes an extensive set of up to 27 genetic markers to deliver the most accurate statistical assessment likelihood of sibling relationships.
- Dual-Process Testing: Every test undergoes our dual-process analysis, meaning your samples are independently tested twice to ensure maximum accuracy.
Understanding Your DNA Sibling Test Results
The DNA Sibling Test compares the DNA of two individuals to establish the statistical likelihood that they are biologically related as full or half siblings. Unlike a paternity test, which provides a definitive answer, a sibling test is more complex because siblings only share a portion of their DNA.
Your final, confidential report will provide a Combined Kinship Index, which represents the statistical likelihood of a sibling relationship:
- A value greater than 1.0 suggests a biological relationship is more likely.
- A value less than 1.0 suggests a biological relationship is less likely.
The further the index is from 1.0 (either much higher or much lower), the stronger the evidence for or against a sibling match.
Read our detailed guide to interpreting sibling DNA results →
Why Choose DNA Tests Direct?
You don’t compromise on the things that matter, and neither do we. For over 25 years, DNA Tests Direct has been the go-to choice for individuals, families, and professionals who need reliable results. We turn uncertainty into clear answers by combining proven laboratory science with a simple, efficient process that works around your schedule.
We pair this technical precision with a deep respect for privacy, ensuring all client information is handled with the highest degree of security. With thousands of satisfied customers worldwide, DNA Tests Direct has become the trusted choice for genetic answers that matter.
Need a DNA Sibling Test for Legal Reasons in the United States?
Painless Mouth Swabs
Secure Online Results
Trusted Laboratory Expertise
Frequently Asked Questions
What is a DNA Sibling Test and when would I need one?
A DNA Sibling Test determines the statistical likelihood that two individuals are full siblings, half-siblings, or unrelated. This test is particularly valuable when a potential parent is unavailable for testing. Common scenarios include siblings separated at birth seeking to confirm their relationship, establishing biological connections for inheritance claims, U.S. immigration cases requiring evidence supporting a sibling relationship, or simply addressing questions about family connections.
How accurate is the DNA Sibling Test?
Our DNA Sibling Test provides a statistical likelihood rather than the definitive “yes/no” results of a DNA paternity test. The test analyzes up to 27 genetic markers through dual-process testing in our accredited laboratory. Because siblings share a variable amount of DNA, results are presented as a Combined Kinship Index, showing how likely the sibling relationship is compared to no relationship. Whenever possible, we recommend testing a known parent directly for the most conclusive results.
What if potential siblings live at different addresses in the United States (or internationally)?
If participants live in different cities or countries, we can split the DNA test kit and ship components to separate addresses. Each kit part is individually barcoded for secure tracking, and testing begins once all samples have arrived at our laboratory.
To request a split kit, include the following in the “Additional Information” section at checkout:
“Please send Person A’s kit to [Name, Address] and Person B’s kit to [Name, Address].”
Note: Additional shipping fees apply for multi-address orders.
Can I use the results from this DNA sibling test in court?
For legal matters such as court proceedings, child custody, social security benefits, or inheritance claims, you will need to order our Legal DNA Sibling Test. This test follows a strict chain-of-custody procedure to ensure the results are admissible in U.S. courts. The process includes having DNA samples collected by an impartial third party, verification of government-issued ID for participants, and having the samples sent directly to the testing laboratory.
Click here to learn more about legal DNA sibling testing →
Does the DNA test kit expire?
No, the DNA test kits do not have an expiration date and can be stored indefinitely before you collect the samples. However, once a sample is collected on the swabs, we recommend sending the kit back to our laboratory within 3 months to ensure the best results.
Can the DNA Sibling Test determine if we have the same father?
Yes, this is one of the most common reasons people order a DNA Sibling Test. The analysis will compare your DNA profiles to determine the statistical likelihood of you being full siblings (sharing both a mother and a father) versus half-siblings (sharing only a mother OR father).
Is the collection process difficult?
The collection process is simple and painless. Your kit includes easy-to-use cheek swabs that you gently rub against the inside of the cheek for about 30 seconds. This collects more than enough DNA for testing without any blood or needles. The process works for everyone, including infants. Your kit includes clear instructions, and our customer service team is available if you need assistance.
