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Frequently Asked Questions

We use the latest DNA-based technology with state-of-the-art equipment. While many other labs use only 5 or 9 genetic markers, we use 16, which is sometimes referred to as a "premium test". This is the most powerful standard DNA test done in the industry. Because of the speed of our equipment, DNA tests can be completed in three days (or less) if needed, although standard turnaround time is 5 workdays. As soon as a DNA test is completed, the results are made available to the customer through our Order Status page. In addition, in the case of court admissible tests, a paper copy of the DNA test report will always be mailed to you for your records.

Question: How long does it take to get the results?

We guarantee to have the results ready in 5 working days from receipt of samples. A shorter turnaround time of 3 working days or less can be arranged for an additional charge (see DNA Testing Catalog). Some tests, including, but not limited to, the X-SV Female Lineage DNA test and the DNA Predisposition test, have a longer turnaround time.

Question: How will I receive my paternity test results?

If you ordered a legally binding test, the test results will always be mailed to the billing address provided, unless an email is sent to info@gtldna.com requesting we ship the results to a different address. Informational test results are always available online and an optional hardcopy result is available for a slight fee. For all internet orders, you can follow your order status and get test results over the internet as soon as they are ready. As a rule we do not give results over the phone, unless we have made prior arrangements with you to do so

Question: How do I interpret the Paternity Test report?

In the vast majority of cases the results produce an unequivocal result. The alleged father is either "excluded" or is "not excluded" as the biological father. Each of the 15 identity loci are analyzed separately to calculate a paternity index, and all the individual indexes are combined to calculate a "combined paternity index". For more information see How to Interpret a Parentage Test Report.

Question: What is the Combined Paternity Index (CPI)?

The Paternity Index is a number that represents the likelihood of Paternity. The number is calculated based on how common the genetic information found in your test result is within your race population. The Paternity Indices for each genetic locus tested are used to calculate a Combined Paternity Index which can result in a 99.999% Probability of Paternity, or even higher in the case of a true match. As an example, if the CPI is 9,999,987 it means the odds of the tested father being the unique biological father are 9,999,987 to one.

Question: Can my results be used in court?

Yes, if you purchase a Legally Binding Test. This kind of test has additional proof of identity and chain of custody requirements. A Legally Binding Test is available either by having GTL collect the DNA samples or by ordering a Legally Binding Home Test Kit. We maintain careful records on every sample processed. Results from the Genetic Testing Laboratory are admissible in a court of law.

Question: Are the results confidential?

Your results will be held in strictest confidence and released only to you. Furthermore, the information obtained from testing the 15 identity loci relate only to identity, and do not reveal any additional information of medical relevance.

Question: How accurate are the DNA paternity test results?

DNA testing is the most accurate method available for determining paternity. Its power lies in the ability to trace the pattern of inheritance for separate regions of the genetic material (chromosomes). From this information a probability of paternity can be calculated. This number can reach 99.99999% in some cases. The percentage of random men of the same race that can be excluded as the biological father is also computed for every case.

Some companies test as few as 8 chromosomal locations for the same price (or more) that we charge for 16 (15 identity markers plus one to confirm the sex of the person). The statistics generated with only 8 locations, however, are not nearly as conclusive, and in some cases can result in wrong conclusions, such as the father being excluded when, in fact, he is the true father.

Question: What is your accuracy guarantee for DNA and paternity test results?

Click here to see our accuracy guarantee. We guarantee such results because of the accuracy of the test (see previous question) and the standards we adhere to in the performance of the tests. First, we are accredited by the AABB as a DNA relationship testing laboratory. Second, we participate in proficiency testing conducted by the College of American Pathologists three times per year. Third, our Ph.D. Laboratory director and director designee oversee the operation and personally review and sign all test reports. You can be assured that our methods and practices adhere to the strictest standards in the nation.

Question: How does a DNA parentage test work?

A child inherits DNA from the mother's egg (23 chromosomes) and the father's sperm (also 23 chromosomes). Each parent contributes half of the child's DNA. The child (and every person) has 23 pairs of chromosomes. For each location ("locus," plural "loci") in a chromosome pair there is a specific DNA sequence. A DNA parentage test works by identifying the specific DNA sequences for multiple loci in the mother, child, and father. If the mother and father are the biological parents of the child, the two DNA sequences at each locus in the child's chromosomes must have been inherited from each parent. Determining paternity and maternity is possible from these DNA sequences. For more information, see How To Interpret A Parentage Test Report.

Question: Where are the DNA tests performed?

You can order Home DNA or Paternity Test Kits or call to make an appointment for us to take samples in many cities across the United States.

Question: What standards are used to ensure tests are performed correctly and DNA or relationship test results are accurate?

We follow the standards set forth by the AABB for performing DNA relationship tests. Because we use 16 genetic markers, results usually are completely definitive. In the case of any ambiguities (perhaps caused by a poor sample), tests are repeated. We offer an Accuracy Guarantee. Specific procedures are in place to protect against switching of samples and to maintain the confidentiality of our customers.

Question: What is the difference between an AABB accredited DNA test and an unaccredited DNA test?

We have devoted a whole page to address this topic. Please see About Accredited Tests for an explanation of accredited vs. unaccredited DNA tests.

Question: Is the legal DNA test different from the informational DNA test?

No. The DNA testing is identical. The only difference is that legally-binding tests require a witness, proof of identity, and special chain of custody procedures. The basic Home DNA or Paternity Test Kit therefore is not legally binding. It is intended as a discrete and private way whereby families can resolve questions without involving outside parties. The GTL also offers a Legally Binding or Legal Home DNA Test Kit that requires an unrelated, third party witness to oversee sample collection: receive the test kit and verify identities and chain of custody.

Question: What is a buccal swab and is it as accurate as blood?

A buccal swab resembles a large Q-Tip. It is used to collect cheek cells by rubbing the inside of the cheeks. It is as accurate as blood. A person should, however, abstain from drinking coffee for a few hours before taking a sample, and smokers should rinse and brush their cheeks with a toothbrush before swabbing.

Question: Can a paternity test be performed without the mother?

Yes, although results will not be as conclusive. This is why we offer an Accuracy Guarantee for a paternity test with the mother.

Question: Why is it better to include a DNA sample from the mother when performing a paternity test?

In a matter as important as paternity, especially Legally binding cases, it is never good to leave room for doubt. Ideally, the mother, child, and alleged father should be tested. A child receives half of their DNA from their mother, and the other half from their father. Because the DNA half that the child receives from the mother will match the mother's DNA exactly, the remaining unmatched DNA will match that of the biological father. Without the ability to remove the mother's DNA from the equation, the possibility increases greatly that results will not be conclusive, which may require testing of additional genetic markers, thus extending the time and cost needed to achieve conclusive results. In general, if the mother is available for testing she should be included. In any event, the testing can still be performed and accurate results achieved without a sample from the mother.

Question: What if I want to test more than one child or alleged parent?

Additional family members can be included in the tests (see DNA Testing Catalog).

Question: How old does a child need to be to perform a DNA test?

A newborn infant can be tested. Taking a sample with a buccal swab is painless, and is not traumatic for the child. Please see more information about our prenatal test for testing before birth.

Question: What happens to my DNA samples once the test is complete?

For Informational DNA Testing cases, we destroy the samples you submit to us immediately following the release of your results. Should you decide that you want us to archive your samples, we will archive them for up to six months for an additional fee. Please contact us if you need us to archive your DNA Test samples. For Court Admissible DNA Testing cases, we automatically archive your samples for six months at no additional cost.

Question: Are results from the Home DNA or Paternity Test Kit admissible in court?

The basic Home DNA or Paternity Test Kit is intended as a discrete and private way whereby families can resolve questions without involving outside parties and is not legally binding. We do offer, however, a Legally Binding Home Test Kit for a small additional charge.

Question: How does the DNA or Paternity Home Test Kit work?

The Home Test Kit contains illustrated instructions and a consent form to be filled out with information about each participant providing a sample. Except for infants and very young children, each person collects his or her own samples; the collection process is simple. Buccal sampling takes about 45 minutes for 3 people, with an additional 60-90 minutes for the swabs to dry. Blood sampling takes about 5 minutes for 3 people. The samples are then returned to labeled envelopes. The samples, plus the paper forms, are placed in the included prepaid mailing envelope and shipped back to our laboratory.

Question: What about Blood Testing?

IMPORTANT! Contact your physician for the collection of blood samples for children under 8 years of age. GTL offers this option because it is faster and easier for you to collect. The procedure involves a small lancet that is used to lightly pierce a finger (most don't even feel it). A small drop of blood is then transferred to a collection card - that's it. There is no difference in cost if you choose buccal (cheek) swab testing.

Question: Can you send a DNA or Paternity Test kit to me discreetly?

We understand the sensitive nature of paternity tests. The kit is sent in a plain mailing envelope with "GTL" and a PO Box as the return address. The included prepaid mailer to be sent back is also addressed like this.

Question: Do I need a court or doctor’s order for a DNA test?

No, you do not need such an order to have GTL perform a DNA test.

However, New York State has specific requirements for DNA testing including: collection by a third party under chain of custody; the specimen must be accompanied by a test order from your physician or lawyer; and specimens must be submitted to and analyzed by a laboratory holding a NYS permit. For more information on the NYS policy, call 1-800-682-6056.

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