top of page


DNA Testing.

To determine whether or not there exists a biological sibling or half-sibling relationship. When two people are trying to determine if they share the same father and the father isn't available for testing, a sibling DNA test is an effective alternative. 

Is He my Brother or my Half-Brother?

Do you want to know if you and your sibling share the same father? Not sure if your children are from the same man? Or do you want to confirm a possible relationship discovered through ancestry testing? There are many reasons for doing a DNA sibling test, and Truth DNA offers the latest technology and accurate testing to resolve questioned biological-sibling relationships. The report is posted to your secure online account 5 business days after all samples have been received at the lab. Every situation is unique. 


When set up as a legal case, results from a sibling DNA test can be used for inheritance benefits, proof of relationship for immigration, and more.

Happy Children

Reasons to get a Sibling DNA Test. 


  • To confirm the truth about a biological relationship

  • Medical history

  • Social Security benefits

  • Inheritance claims

  • Immigration cases

  • Insurance claims

  • Results are completely confidential, and your private genetic information is never shared with or sold to outside parties.

See our privacy policy here.

For more information call 888.995.4DNA

Lab Experiment

When set up as a legal case, results from a grandparent DNA test can be used for court.


There are two types of relationships that siblings can share: Full siblingship and Half siblingship. Full Siblings will share two common parents and Half Siblings will share just one common parent. A siblingship test provides the likelihood of genetic relationship between two possible siblings, specifically when no other relatives are available for study. Please note that a grandparentage or reconstruction test is more definitive than a siblingship test, especially if the mother is not involved.



Full Siblingship with a Common Parent Participating

  • A full siblingship test can be performed if the two individuals (Sibling 1, Sibling 2) know they share the same mother, but want to know if they share the same father (who is unavailable for testing).

  • Full Siblingship without a Common Parent Participating

We can perform a full siblingship test even if the mother is not available for testing. The mother’s participation is always encouraged for more conclusive results.

Half Siblingship with Two Parents (not in common) Participating

A half siblingship test is performed if the two individuals (Sibling 1, Sibling 2) know they have different mothers but want to know if they share the same father (who is unavailable for testing).

Half Siblingship without Parents Participating

We can perform a half siblingship test even if one or both mothers are not available for testing. However, a mother’s participation is always encouraged for more conclusive results.

Turnaround Time

  • Five (5) business days from receipt of all samples



Chain-of-Custody Requirements

  • Chain-of-custody requirements must be fulfilled for test results to be defensible in any legal situation, such as inheritance disputes. These requirements include the following:

  • Samples are collected by a neutral third party, such as a clinic or laboratory

  • The individuals tested are positively identified (i.e., they present a government-issued ID to be photocopied and/or they are photographed and fingerprinted)

  • A standard kit is used. Each party completes and signs a Client Identification and Consent Form (COC-4002-CA)

  • Guardianship of tested minor must be verified at the time of signing consent

  • The kit may not be in the possession of the clients prior to or after being collected

Non-Chain-of-Custody Requirements

  • In a non-chain of custody test, samples are collected by the patients themselves. Results of this test are for personal knowledge only and may not be used for legal purposes

  • An in-home kit is used, and buccal samples can be collected by the patients themselves at a time and place of their choosing

  • Since the origin of the samples cannot be verified, names are listed on the report in the same way they are labeled on the samples

  • A unique barcode is assigned to each kit and appear on the report as a reference for the case

  • Barcoded kits are assigned to your account for easy reference


  • Generally speaking, biological-relationship testing such as genetic reconstruction and siblingship testing is not as definitive as DNA parentage testing. It is not possible to determine with absolute certainty whether two people are siblings or biologically related in some way other than the parent-child relationship. We can only test whether they are more or less likely to be related

  • Including any biological parent, such as the mother, increases the probability of obtaining conclusive results. Results may be inconclusive without her participation and further testing with additional relatives may be suggested by the laboratory

  • Results show a Combined Siblingship Index, a statistical value showing the genetic odds in favor of the relationship and a probability of siblingship in the form of a percentage. This number represents the number of times that the tested individuals are more likely than not to be biologically related as siblings in the manner it was tested

  • A siblingship rider form is required at the time of testing to ensure we are performing the proper test for your client

For more information call 888.995.4DNA

More about this Test

  • Instagram Truth DNA
  • Truth Ancestry
bottom of page