Ordering your test

Your sibling DNA test will be carried out in an ISO 17025 accredited laboratory. These accreditations are the most widely recognized global accreditations, proving the scientific and technical know-how of the laboratories analyzing the samples of DNA.

Results for this test are ready in 5-7 working days from the moment we receive samples, and will be sent by email.

We suggest you return samples by courier directly to the laboratory because the local postal system has proved unreliable and we cannot be responsible for samples that do not reach us.

PLEASE NOTE: In the event of a possible pre-existing relationship the laboratory would NOT be able to run a sibling test if you believe your cousin could be your sibling. Please contact us to help you find the right test for you.

Sibling DNA test results

Siblings testing is done when people taking part in the DNA test are males and females. If the interested parties are of only one gender, then we may recommend other types of relationship testing depending on the gender of the people in question. Sibling test results are made more accurate by the inclusion of the mother’s DNA sample. We strongly suggest including the sample of a known mother to provide stronger results.

Our sibling results will show a relationship index. This index can either be greater than 1.0 or less than 1.0. Individuals that are not full siblings and share neither of their parents will have a relationship index value that is less than 1.0. On the other hand, full siblings sharing both biological parents and half siblings sharing only one biological parent will have a relationship index of more than 1.0.

The result will also provide an interpretation by our scientists, detailing whether the people tested are more likely full siblings, half siblings or perhaps not siblings at all.

Collecting your samples

Home testing is the way of going about a peace of mind tests these days. No more blood samples or visits to clinics. All you need is the home kit which we supply. Inside this kit, you have the oral swabs for collecting samples as well as the instructions and consent forms. Interested in seeing just how simple sample collection is? Visit this page.

Other testing options

If individuals interested in carrying out the test are males homeDNAdirect South Africa suggests a Y chromosome test. This test will confirm a shared male line between the people tested.

If test participants are female an X chromosome test would be the ideal test. We suggest reading our web page for more information about X and Y chromosome testing.

Note that X chromosome testing between females with the same mother who wish to establish whether they have the same father can only be done if the mother’s sample is included.

A sibling test is often done by people who wish to know whether they have the same biological father but opt for a sibling test instead of a home paternity test as they do not have access to the alleged father’s sample. Sibling tests can be conclusive but never as conclusive as a paternity test. The fact that you are trying to confirm the biological relationship between two people in relation to a missing, alleged parent makes siblings tests less accurate than a paternity test carried out directly with the sample of the alleged father.


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