How Accurate Are DNA Tests?
Each of us has a unique signature that lives within every cell of our body. This signature is commonly known as DNA, or the building blocks of life. No two people (with the exception of identical twins) have the same DNA structure. We get our DNA from our biological mother and biological father. Each of them contributes 50% of our chromosomes that will make our up our DNA – this same DNA will stay with us for our entire lives without change. This is the very reason that makes DNA such a great choice for uniquely identifying a person.
Testing can be done on DNA to help determine parentage, ancestry, presence of genetically based diseases and to help identify someone who may have been present at a crime scene. Questions may arise as to how accurate DNA tests are. After all, in the past blood tests can not been as accurate as we might have hoped. They often left a bit of uncertainty or could not be conclusive in many areas. But thanks to the uniqueness of DNA almost all of these doubts can be taken away. Modern testing procedures and rules for DNA analysis mean that with rare exception DNA testing results can be guaranteed to be 99.99% accurate for most paternity, forensic and genetically based disease analysis.
DNA testing is done by taking DNA extracts from biological testing, putting them into a gel matrix and then using probes to help extract certain markers. Most DNA tests are run at least twice, both independent of each other. This not only builds upon the credibility of the test but also helps ensure that no wrong data or incorrect marker analysis was performed on the first test. If any discrepancies are detected between the two tests then a new sample is used (when samples are collected there is usually an abundance of DNA present) and the entire test is performed again to understand where the discrepancy may lay.
You may have heard the term court-approved test used before when referring to DNA tests. Certain courts, in fact a majority of them, do not approve of the use of at-home testing as evidence. This is because the accuracy of the samples collected cannot be guaranteed – if there is any area where the accuracy of a DNA test can be affected it is in the sample collection process. When at-home tests are performed there is no way for a court to guarantee the samples came from who they say they did. In this situation court-approved testing involves the use of collection of the samples by licensed personnel who also verify the identity of the person who is providing the samples.
Of course, as with anything in life human error can come into play. A lab may mistakenly switch samples or key in data incorrectly. All of these factors are possible, but also are very rare in occurrence. If there is ever any doubt as to the authenticity or correctness of a test it can simply be performed again to confirm accuracy.
Overall, DNA tests are the most accurate tests we have for using in situations where we need to know the positive identity of someone. They are the tests that do not lie, and cannot be influenced by taking drugs or other substances – unlike blood tests which can be fooled by certain substances. It is because of this accuracy and “cannot tell a lie” DNA tests that they have become so commonplace in our society. They will continue to gain popularity and usage as science discovers more areas that DNA can assist us in. They are here to stay and without fail will always tell the truth, whether we like that truth or not.