Can Paternity Tests Be Inaccurate?

Paternity DNA tests are more than 99.9 percent accurate, according to manufacturers. No two people have the same DNA, except in some cases of identical twins. In fact, the chances that two individuals (who are not identical twins) have the same DNA are one in several billion.

Comparing DNA to the Mother

The first step is collecting DNA from the child, which is then matched to that of the mother. This takes care of 50 percent of the chromosomes; the rest belong to the biological father.

Comparing DNA to the Father

The next step is extracting a DNA sample from the presumed father and comparing it against markers and bands in the chromosomes that have been pinpointed in the child's DNA.

Importance of Band Match

When probe markers find a band match in the DNA, the number of bands to match grows and another test is carried out. The more bands that are matched, the greater the validity of paternity.

Invalid Paternity Test

Hardly any conditions would invalidate a paternity test based on DNA. But two circumstances that would are DNA contamination and not knowing the source of DNA. The solution is performing another paternity test using new samples from the child, the mother and the suspected father.

Paternity Testing at Home

Paternity testing in some states such as California can be performed outside of the courtroom. Several companies offer at-home testing where you collect samples using a buccal swab. You rub the buccal swab on the inside of the cheek of your mouth and then put the swabs in a container provided to return to the laboratory.