A person's DNA (deoxyribonucleic acid) represents a "genetic blueprint" and, like a fingerprint, is unique to each individual. DNA is the basis for linkage in familial relationships and thus, allows for determination of specific existing relationships.

The genetic information of a child is inherited from both his/her biological parents and cannot be purposely altered in any way. An individual's genetic information is encoded in DNA, within the 23 pairs of chromosomes, in which one chromosome from each pair is passed down from each parent. As the genetic structure of an individual is innate, there is no age limit as to when DNA samples can be collected. In DNA paternity testing, analysis of the child's genetic profile in comparison to that of the alleged father will prove paternity inclusion with >99.9% certainty for an existing biological relationship if one chromosome within each pair from both individuals match perfectly. Similarly, a 100% paternity exclusion can be proven if the genetic information between the two participants indicates signs of variation.