One question on many people’s minds when they look into paternity testing is how accurate the paternity test results are. No test can ever be 100% accurate but how accurate can you expect your paternity test results to be and what should you expect from a DNA testing lab?

There are two results involved in a paternity test, the first is called exclusion. Exclusive paternity test results exclude a man from being a father of a child. This means that in the paternity test the DNA of the father did not sufficiently correspond to the DNA of the child to consider him as a prospective father. In this case the result should be 100% accurate, if a man is excluded from being a child’s father there should be no way he could possibly be.

Inclusive paternity test results however are different, they refer to the likelihood that someone is the father of the child. Although no test can ever be 100% certain most paternity test results should prove at least 99%, preferably closer to 99.99% that a child is the father.

The accuracy of paternity test results depends on how many loci (or points) are tested on the DNA segments of the alleged father and child; the higher the number of loci, the greater the accuracy that can be obtained.

To get the best results from your paternity test you should choose a laboratory that tests at least 13-16 loci and that excludes fathers who show a difference in two or more DNA patterns on the loci (this is the AABB standard that is used in accredited DNA testing labs).

In conclusion, although paternity test results can never be 100% accurate you should look for at least 99% accuracy and preferably closer to 99.99%. Accuracy is obtained through testing a larger number of loci and good DNA testing labs usually test about 16.