How DNA testing works
Children receive half of their DNA from their fathers and half of their DNA from their mothers. Each piece of genetic information that makes up the DNA in a child is present in either the mother’s or the biological father's DNA. The samples Memorial Blood Centers collects are tested for genetic markers (pieces of DNA) in an individual that are inherited from both parents. These pieces can be compared between people to determine relatedness. Only one man can be the biological father of the child.
To establish paternity, multiple genetic systems are tested. These systems exclude at least 99 percent of all falsely accused men. If a man is included as a potential father, a combined relatedness index (the odds that an accused man is a potential father) and the probability of parentage (the weight of all the genetic evidence gathered expressed as a percentage) will be calculated.
Types of testing