The certainty of what happens at a cellular level puzzled many for centuries. That is until the discovery of DNA and the development of the DNA test. Today, diseases, ancestry, biological parenthood, forensic science in court cases and many other issues can be determined with certainty thanks to our knowledge of the human genome and DNA. Even though DNA analysis is still relatively new it is quickly becoming popular in many fields outside those of genetics. Nutritionists, health care specialists and even average individuals are for some reason or other, turning towards these tests.
How accurate is DNA testing?
The tests are extremely accurate as well as precise, with the slightest margin of error (although might be worth adding at this point that the type of DNA test and the sample used could and do affect the accuracy).
But just why is the analysis of DNA so absolute you may wonder?
Every individual has a unique DNA code that no-one else possesses and because of this reason there is not a chance in receiving an inaccurate result, except in cases where contamination may have occurred. If contamination has taken place, the results obtained would be inconclusive. This was a major issue in the Amanda Knox trial, where careless forensic sample collection led to contamination of the DNA.
There are various DNA tests for different reasons, such as, ancestral testing, forensic identification, disease diagnosis and biological relationship testing. A DNA test is performed by collecting a small tissue sample for analysis and then extracting a single strand of DNA from the human cells for typing. The sample obtained does not affect the results because the genetic makeup remains constant in all human cells. Whether it is a skin, hair, semen, saliva or blood sample obtained, the results will still be as accurate as ever once DNA is extracted. The DNA strands are then analysed for determination of the genetic makeup of the individual. DNA analysis is usually performed in laboratories with advanced equipment to ensure that correct results are obtained. However, test kits have been developed which can allow many to perform the test at home. The tests are primarily used for relationship tests such as maternity and paternity testing.
DNA testing is more accurate than blood testing because blood types are not unique to particular individuals. Several individuals can share a blood group. Therefore, the blood tests are prone to errors if used for identification, parental testing or ancestral determination.
What is the accuracy level of the DNA paternity test?
There is no test that is 100% accurate since the results of every test are determined by several factors. However, you definitely need a result that is very precise and accurate. In paternity testing the first test is usually called exclusion; that is, ruling a man out as the father of a baby. Men are ruled out if their DNA does not adequately correspond with the DNA of children. The second form of DNA paternity testing is called inclusive testing. The test determines the probability that a man is the father of the child. The results of a paternity test with a 99.9% outcome will indicate that the tested alleged father is the biological father. With an unprecedented level of accuracy, the result of a paternity DNA analysis is absolute.