Paternity test
A paternity test is a test which establishes whether there is a biological link between a man and child by examining their DNA. As DNA is directly inherited from parents, looking at the DNA of a child can help to identify the biological father when the child’s DNA is compared to the man's DNA.
A swab sample can be taken from the inside of the cheek of the child and of the father, in order to collect DNA for examination, however if the mother is also tested, this allows for a test result that is almost 99% accurate as it rules out the mother’s genetics to allow complete verification of a father–child link.
As the Y chromosome is passed directly from the father’s side, this is the comparable area for analysis. This enables paternity to also become established through testing blood samples. The DNA of the father is taken, as is that of the child’s, and where possible the mother, and then are isolated and examined in the lab.
The DNA samples of the individuals involved are then broken down to see if there is a matches on every DNA ‘probe’, or part of the DNA that can be isolated. Because a father and mother pass on 23 chromosomes each to the child in an equal amount, if when comparing the father and child’s DNA in the test two or more of the ‘probes’ do not match then the man will not be the child’s father. If all match, then the probability of paternity is practically 100%.
