How does a DNA test work?
Determining a child's paternity may be necessary when matters of child support, child custody or adoption are involved, and DNA testing is used to examine DNA markers and look at the relationship between two people. When Illinois residents undergo DNA testing, samples from a mother, child and alleged father are taken. These tests have a 99 percent certainty rate or higher.
Upon conception, a child inherits unchanging genetic material from its mother and father. DNA testing compares the genetic characteristics of a child to a mother first and then a potential father, and a father must have the characteristics a child has that the mother does not. If a man and child share some of the same DNA, a laboratory calculates the likelihood that the man is a child's biological father.
Samples for DNA testing are usually collected with a mouth swab because a cheek swab is as accurate as blood testing but is painless and simple. When samples of a mother, father and child are involved, testing normally takes around three to four working days. The results of a DNA test are admissible in court, and laboratories that conduct DNA testing must be accredited by the American Association of Blood Banks. Scientists and lab technicians with experience in genetic testing conduct the tests, and labs must follow strict procedures when testing to ensure reliability, which makes the results admissible in court.
When a couple goes through a divorce or decides on child custody matters, both parents have rights and responsibilities in relation to any children. Proving paternity may be necessary when a father wants access to a child, and DNA testing is also necessary if a man believes he was mistakenly ordered to pay child support. Parents are advised to seek separate legal representation when going through the process.
Source: Genetic Profiles Coporation, "How does DNA paternity testing work?", November 05, 2014