DNA testing is sometimes referred to as DNA fingerprinting. It is called a fingerprint because it is very unlikely that any 2 people would have exactly the same DNA information, in the same way that is is very unlikely that any 2 people would have exactly the same physical fingerprint. The one exception to that would be with identical twins, or monozygotic twins. When one egg is fertilized by one sperm cell, and then divides and separates, two identical cells will result. Monozygotic twins are genetically identical (unless there has been a mutation during development) and they are almost always the same sex.
Only a small sample of cells is needed for DNA fingerprinting. DNA testing can be done on cells obtained by a simple swab of the cheeks inside the mouth, a drop of blood, root of hair, or semen. The process of collecting these specimens is a very simple process, but if not done properly can lead to inconclusive results. Although home paternity test kits are available, they are not as accurate and the results cannot be used in a court of law.
In the United States, AABB regulates DNA paternity and family relationship testing industry. Only the DNA test results produced by an AABB-accredited laboratory are legally admissible and accepted by government child support agencies, welfare benefits offices and immigration authorities. The DNA paternity test that follows strict chain of custody can generate legally admissible results that are used for child support, inheritance, social welfare benefits, immigration, or adoption purposes. To satisfy the chain-of-custody legal requirements, all tested parties have to be properly identified and their specimens collected by a third party professional who is not related to any of the tested parties and has no interest in the outcome of the test.
DNA testing is currently the most advanced and accurate technology to determine parentage. In a DNA parentage test, the probability is 0% when the alleged parent is not biologically related to the child and the probability typically greater than 99.9% when the alleged parent is biologically related to the child.
Genetic testing used to determine the biological father of a child is called a DNA Paternity test. Every person carries two copies of most genes (one copy from the mother and one from the father). DNA testing is a a test to identify and evaluate the genetic information called DNA (deoxyribonucleic acid) in a person’s cell.
