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Why do some samples fail analysis?

There are several reasons why analysis of a sample may not be successful, and it is not always known why it is more difficult to analyze some samples over others. If necessary, the lab will make multiple attempts at all stages of the process in order to provide results; however, due to biological variability some people simply don't have a high enough concentration of DNA in their saliva for our technology to process.

If your sample has to repeat one of the analysis steps, your sample status will update; both DNA isolation (Step 3) and DNA analysis (Step 4) may be repeated.

In the event of an analysis failure that requires a second sample be provided, you will see a notification within your account in one of the following formats:



Replacement Sample

You will also receive an email in the event a replacement needs to be requested. When submitting a replacement sample, we recommend reviewing the tips on providing a good sample, including:


Do not eat, drink, smoke, chew gum, brush your teeth, or use mouthwash for at least 30 minutes prior to providing your sample.


Collect the recommended volume of saliva. The recommended volume of saliva to provide is 2 mL, or about ½ teaspoon. Your saliva sample should be just above the fill line.


Provide your sample and add the stabilization buffer within 30 minutes. The full saliva sample should be collected within 30 minutes and the funnel contents should be released into the tube immediately. Waiting longer than 30 minutes may decrease the yield and quality of your DNA.


Cap securely before shipping. Remember to remove and discard the funnel lid and place the tube cap on securely before mailing your sample to our laboratory.

Receiving a Refund

In the event that analysis of your sample is not successful and you would prefer to receive a refund instead of submitting a second sample, you can do so from within your account. To receive a refund, click the “Request a refund instead” link from within your account.

If you have already submitted two different samples and both samples had either insufficient DNA or a low call rate, there are no known steps that will increase your likelihood of receiving results from an additional analysis attempt. Our laboratory has already attempted to extract a viable sample from your saliva at least 4 times. Even when all directions are followed precisely, a small number of individuals may not be able to receive results from their samples. You will be able to request a refund from within your account in the event of a second failure.

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