It is important that a DNA paternity test be accurate. There are two basic ways that a DNA paternity test can be reported incorrectly. There is the false positive and the false negative. Both can be devastating to the persons involved so a lot of care must be taken to prevent issuing false results.
A DNA paternity test can be a false positive when the results are reported has being positive when they are in fact negative. This happens rarely, but is still a possibility. One example of how this can happen on a DNA paternity test is that the testing laboratory fails to analyze the DNA completely. When only a small number of loci are used for the test there can be matches with very common sizes that may be shared coincidentally. False positives can also occur when people involved in the DNA paternity test are closely related. For example, two brothers may be the father of a child in question. This can be tricky because, since the bothers are related, they share a lot of the same DNA. These pit falls can be avoided by testing as many loci as possible.
A false negative is the opposite; it is when a negative result is reported when that is not the case. This can happen if samples get mixed up in the laboratory. Great care must be taken to always make sure that samples are properly handled from the beginning of the test, at the collection, and on through all of the processing and handling. Samples need to be clearly labeled and handled in a way that there is no chance of mix up or contamination with other samples. Another possibility that could lead to a false negative is mutation. Sometimes mutations randomly happen, very rarely, but they do happen. For example, the DNA the child inherited from the father has changed and is now slightly different than the father’s. If the DNA analysts see a mismatch the normal presumption is that the test is negative so care must be taken to pay attention to the possibility of mutation. This is done by looking for more than a single mismatch before reporting a DNA paternity test as negative.
Regardless of which kind of false result is reported in a DNA paternity test, the results of a false test can be devastating. In many DNA paternity tests there is the need to establish paternity to assign child-support responsibilities. A false negative can leave children with out child-support; a false positive can peg financial burdens on man who is not really responsible. A DNA paternity test or any other relationship test is a tool to unravel complicated situations. People’s lives can be inherently tied up with the results of a test. The DNA paternity test, above all, needs to be factual. The DNA testing laboratory has a duty to carefully and accurately report the results of a DNA paternity test.