Are you really brothers? Do you think they are children of the same parents? 

The Sibling DNA Test is ideal for situations in which the alleged siblings (male and female siblings) want to confirm their biological relationship and verify if they really are siblings, step-siblings or if they do not have any biological link in common. The test is quick and is done through a saliva sample that must be done by the brothers using a cotton swab.

The Sibling DNA Test is usually highly recommended when the people who are part of the test are the male and the female. This type of test establishes the proportion of common DNA between both people tested. This test is based on a mere statistical probability.

Unlike a paternity test, sibling DNA testing does not need to provide genetic profiles that respond to different genetic markers. A sibling test will simply seek to determine whether or not the tested individuals share a biological link in common, that is, whether they are both the joint children of the same parents, or have only one father or one mother in common.

In a DNA test between siblings there is an index called: brotherhood index; if the brotherhood index is less than 1.00, it will indicate that there is no relationship between the two participants. If the sibling index is greater than 1.00, it will indicate that the people participating in the test are siblings or step-siblings, most likely true siblings or full half-siblings.

Is there any limitation for sibling testing?
No, there is no limitation for the sibling test since only a biological DNA sample from each of the participants is enough to be able to make the comparison between the two. In addition, DNA remains of the possible and alleged parents are needed to carry out the genetic verification, and if it is indeed their biological father and mother, or they are children of a different father or mother.

How much genetic code do siblings share? How much genetic code do siblings share?

On average, siblings share about 50% of their DNA in common.

But unlike a DNA test between the alleged father and son where each genetic marker needs to be compared, a sibling test does not require a complete comparison of each marker.

When profiles of suspected siblings are compared in our lab, our scientists determine the amount of common DNA that exists between tested individuals. This is known as the guild rate - which we noted above this text entry - and all guild tests assume an approximate 50% chance. This means that we make the statement that there is a 50% chance that they are related and a 50% chance that they are not.

The greater the probability of a relationship between the two siblings, the greater and more accurate are the chances that the two siblings share the same biological parent(s). If this were to be the case, assuming that the lower the probability this would lead to the interpretation of the same results, the less likely it is that the siblings share the same biological parent(s).

If you do not know how to make the homemade DNA kit, we leave you the instructions in this link: Build DNA Home Kit and perform the genetic test step by step.

Is it possible to carry out the DNA test only between siblings of the same sex?

If the siblings are male, and they both want to know if they share the same biological father, we advise that they both participate in the Y Chromosome DNA test as it has higher efficiency and statistical probability of accurate results. In the case of female sisters, if they both doubt whether they share a common paternal line, they can request a male blood sample from a direct relative and participate in the Y Chromosome Test.

What are the different variants of the brotherhood test?

Our sibling test is safe, fast, reliable, and cheap.

It can be done for legal purposes to present in court. In these cases, there is not only a need for family recognition, but marital property and inheritance are at stake. It is also necessary the presence of those involved with their respective identity documents, and the proper authorization in case of being a minor or minors. The presence of a judge is not required and it is face-to-face yes or yes.

The other different variant that exists of this genetic test is the anonymous modality. On this occasion, there are no judicial procedures, and the study is not valid in legal instances. This DNA test can be done through the kit that we deliver through our laboratory or through a remote DNA test, building the home DNA kit yourself to send us the samples to our laboratory to be analyzed and that you can obtain your results.

If you wish to perform the DNA test with the saliva sampling kit, you can find the instructions at the following link: Perform DNA test with laboratory kit, step by step instructions.

Our DNA tests have the best prices in the entire market. Unlike other laboratories that are usually more expensive than others, our prices are the cheapest, because there are no third parties or intermediaries that can increase the price.