DNA Test for Twins & Siblings

Wouldn’t it be exciting to discover if you or your children are fraternal or identical twins, or even to identify a new-found sibling? With our Twin and Sibling DNA testing, you can get these results quickly and painlessly with a simple at-home test.

3 Different Tests

Dependent upon the familial structure, there are three different Sibling DNA tests:

  • Full Sibling vs. Half Sibling – this test will determine if two people share one or both parents.
  • Half Sibling vs. Unrelated – this test will determine if two people share one parent.
  • Full Sibling vs. Unrelated – this test will determine if two people share both parents or have none in common.

After your order is placed, Rapid DNA Testing will contact you to acquire all the pertinent information.  For example, if two people wanted to use the Full Sibling vs. Half Sibling Test to determine if they share the same father, it would be important to inform Rapid DNA that they share the same mother.


To determine whether the relationship between twins is fraternal or identical, the Twin Zygosity test will analyze specific markers. This test is convenient and easy to do at home. This test won’t leave any doubt.

Twins are either ‘identical’ or ‘fraternal’. In as little as a few days you could learn whether you or your children, are ‘identical’ or ‘fraternal’. How great would that be?


Our sibling DNA test is 100% accurate and results can be completed within 5-10 business days.


With the most comprehensive Sibling DNA Test in the United States, you can get definite result where other tests would fail:

  • Prove a sibling relationship between two people
  • Analyze as many as 41 DNA Markers
  • Guaranteed accurate and reliable
  • Our laboratory network is aaBB certified
  • Pricing is per test subject

Our siblings test method which employs up to 41 DNA markers gives you definitive results in nearly 99% of cases versus other labs that merely provide 80% of cases.

Ordering Procedures

Ordering is easy online or by phone (866.873.0879). Upon order placement you will receive an easy-to-use specimen collection kit from Rapid DNA Testing. If two kits need to be sent to two different addresses in the U.S. or across the globe, please call Rapid DNA Testing so that we can send them directly to each test subject.

In order to ensure no confusion about the precise sibling test to be performed and relationship to be tested, upon receipt of your samples you are assigned a DNA testing case manager.

Our unique testing produces analyze up to 41 DNA markers to make sure results are as accurate as possible. Our goals is to provide a 99.99% positive or 0% negative results, but occasionally the DNA sample doesn’t allow for those statistics. In these unusual instances, results may be 80% positive or 15% negative.  Test results are usually available within 5-10 business days.

Participants of this test should be two supposed full siblings or half siblings. Including a parent in the testing is highly recommended, but not entirely necessary. Results of the tests are improved if more known relatives can be tested. Specimens from those included in the test can easily be gathered at home, or at one of our DNA collection centers if more convenient. These samples are taken using a sterile swab of the inner-cheek.

Progressive Technology

Rapid DNA provides the most exact results available thanks to our analysis of up to 41 DNA markers and the double run of every test to guard against errors.

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