Grandparent Testing

Grandparent DNA Test –  44 Marker

$199 for two people includes delivery of results in 2 business days

Grandparent dna test

We guarantee our 44 marker DNA test is the most accurate Grandparent DNA test available.

When an alleged father is not directly able to be tested, at least one of his parents can perform a DNA grandparent test to help determine if he is the true father of a child. Biological parents contribute equally to their son’s DNA, so that one-half of his DNA comes from each parent. When that child becomes a father, he in turn contributes to half of his child’s DNA. Therefore, half of the grandchild’s DNA comes from the grandparents, through the son.

Bio-Gene’s Grandparent DNA Test determines the  statistical probability that a person is the biological grandparent of a specific child. This DNA test requires the participation of at least one possible grandparent and the child. In cases where privacy is desired it is not necessary for the grandparent to disclose that that child is being tested.

Unlike a DNA paternity test which should always provide a conclusive result, grandparent relationship tests are a little different. When a grandpaternity test is conducted, our DNA testing laboratory will determine the genetic profiles of both the child and the grandparent(s) whose DNA samples are submitted for examination. Based on the type of genetic material exhibited by each person, a kinship index is determined. If the index is less than 1.00, this indicates non-relatedness. If the index is greater than 1.00, this indicates that the two tested individuals are more likely to be true biological grandparent. The higher the value of the index, the greater the likelihood that the two individuals are true biological grandparent(s) and grandchild(ren).


grandparent dna test accuracy

Private At Home Grandparent DNA Testing

Bio-Gene DNA Testing will only perform private peace of mind, at home grandparent DNA tests using a 44 genetic marker basis. While this much higher than the industry standard, we have found that it is always in our clients best interests to perform a higher marker test for accuracy. We believe you should get the right answer the first time you test. We do not perform 16 marker grandparent testing under any condition.



Test Type

Turnaround Time


1 Person (Addition to Existing Case) 2 business days $125 »
2 People (1 Grandparent/1 Grandchild) 2 business days $199 »
3 People (1 Grandparent/2 Grandchildren) 2 business days $299 »
3 People (2 Grandparents/1 Grandchild) 2 business days $299 »
4 People (1 Grandparent/3 Grandchildren) 2 business days $399 »
4 People (2 Grandparents/2 Grandchildren) 2 business days $399 »
5 People (1 Grandparent/4 Grandchildren) 2 business days $499 »
5 People (2 Grandparents/3 Grandchildren) 2 business days $499 »



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How DNA Samples Can Be Collected

The best method of DNA collection and testing is to use a buccal swab, which is similar to a “Q-tip” cotton swab, which has been rubbed on the inner cheeks of the mouth of those being tested. Sometimes it is not possible to obtain a buccal swab sample, for many reasons, including if the testing is being done discreetly.

We are able to test alternative samples, normally at only a slight extra cost. The non-swab sample should have been stored in a paper envelope or temperature controlled environment. The sample ideally should not have been stored in a plastic bag for an extended period at of time. Some of the alternative samples that can usually be tested include:


Amniotic Fluid

Cups / Bottles

Feminine Hygiene


Band aid (Used)

Dental Floss



Chewing Gum


Hair (With Root)


Cigarette Butt

Electric Razor

Hat (Well Worn)


Condom (Used)

Envelope / Stamp




While we will always do our best to extract usable DNA from non-buccal swab samples, and we have a very high success rate in finding DNA on a lot of different samples, there is no guarantee that sufficient DNA can be found on an alternative sample that is submitted.

How Accurate Is The 44 Marker Grandparent DNA Test?

Please take a moment and review our case studies below to learn about why our 44 marker tests are the most accurate tests available.

Using our 44 marker specialized testing process we are able to take a statistical approach by testing only one grandparent and child, and in almost every case obtain a conclusive result without the inclusion of the mother. Our statistical method uses this approach: we all have four grandparents and each has donated 25% of our genetic profile. The calculation determines if it’s more likely that a grandparent and child share 25% in common or share what two random unrelated people would share in common. When less people are tested, more markers are needed.

If the situation occurs that it is deemed necessary to test another grandparent’s DNA, orto add the mother’s DNA sample, to make certain we have conclusive results, neither the child or original testing grandparent will need to retest.


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The following case studies are provided to demonstrate the difference between results from a 16 marker grandparent test and a 44 marker grandparent DNA test.  

Case 1

A grandmother and child are compared to determine if her son could be the father. After testing 16 markers, it is found that there was only a 30.0% (69.20% unrelated) probability of relationship. We report any probability less than 80% as inconclusive, to match our legal tests. Scientifically, you cannot draw a conclusion from the information when it is below 80%. We asked for the mother’s sample and tested with the 16 maker test. The results were also inconclusive with a probability or relationship of 43.88% (56.12% unrelated). After testing 44 markers, the probability of the grandmother being related dropped to 0.01%, meaning that she was 99.99% probable to be unrelated to the child. He son was not the biological father.

grandparent dna test results


Case 2

In another grandmother and child comparison with 16 markers, the results were found to be a probability of relationship of 27.09% (72.90% probable to be unrelated). The mother was unavailable for testing and we proceeded with the 44 marker test. We found the probability to be 99.70% in favor of a relationship with the child. This illustrates the power of additional markers being testing, and why our inconclusive level is set at 80%. The 16 marker test is simply not strong enough and, at times, can produce misleading results as proven by this case.

grandparent dna


Case 3

This grandmother and child DNA comparison with 16 markers produced a nearly equal probability of being related or unrelated at 48.85%. After testing 44 markers, the probability increased to 87.26% probability of relationship. This was sufficient to demonstrate a biological relationship.

grandparent home dna test


Case 4

In this case, the alleged grandfather, child, and mother were tested. The probability of relationship at 16 markers was 57.56%, which is inconclusive. The probability increased to 99.99% after testing the three participants with the 44 marker test.

private grandparent test


The conclusions that can be drawn from these cases is that a 16 marker DNA test will not produce conclusive results, in most cases, when performing a grandparent DNA test.

What The Grandparent DNA Testing Results Look Like

Due to performing a high marker test, Bio-Gene DNA Testing is able to deliver results that show conclusive results in almost every single case we handle. The sample result below show how the genetic code is listed (left hand side), and how the results are given (upper right hand side). In this case we were able to determine beyond a reasonable doubt that the son of the paternal grandparent in question was NOT the biological father. In deal with probabilities, 90% or greater is commonly accepted as proof for or against biological relationships. In the even that the son of the grandparent being tested was the father of the child, the results would have shown the probability that they WERE kin.

Sample Grandpaternity Report:

Grandparent DNA test


The results are clear, understandable, and are definite. Testing results are always kept confidential and only shared with the person ordering the test, unless specific instructions have been given to do otherwise. Our Genetic Consultants are also available during regular business hours to review you results with you if you have any questions at any point at 1-844-BIO-GENE (246-4363).

How to Order a Grandparent DNA Test

How it works graphic


To order your Grandparent DNA test kit, please complete the order form by clicking on the ORDER NOW button. Our prices can be found by selecting the test of your choice, the number of people testing, and your payment preferences when providing the information that is relevant to your particular case. When ordering a grandparent test you may choose to purchase a testing kit from Bio-Gene DNA Testing or make your own DNA kit. This may be especially helpful is you are using alternate samples, or do not want to wait for the testing kit to arrive to your shipping location due to time constraints.

If you chose to use a Bio-Gene DNA Testing DNA collection kit, you will choose the shipping option that is right for you. Once your kit is mailed, you will be provided a tracking number to be able to determine when it will arrive. We do not ship kits without a tracking number.

grandparent dna test kitIf you choose to use your own kit, you will choose the “own kit” option when choosing the shipping options, and upon receipt of your order you will be e-mailed a submission form (within 4 hours of your order during regular business hours), a unique ID number that relates to your case (we cannot process any DNA samples or being testing without a case number), detailed instructions on how to collect and ship the DNA samples, and our lab’s address to send your DNA samples to for immediate processing.

To learn about using your own DNA testing kit, please click HERE. We strongly encourage the use of your DNA testing kit for those needing testing who live outside of the United States.


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If you have additional questions you can-mail us at, or you may call one of our Genetic Consultants at 1-844-BIO-GENE (246-4363) to discuss your case confidentially.