The science of DNA profiling relies on technology that allows an individual's DNA (deoxyribonucleic acid) to be examined and analyzed. DNA is the genetic material that we all inherit from our parents; half from the mother and half from the father. It is considered the genetic blueprint that makes each of us unique. The one exception is identical twins, who have identical DNA. The complete genetic blueprint is found in all nucleated cells of the body. Thus, DNA profiling can be performed from many types of biological specimens including blood, buccal (mouth) swabs, sperm, autopsy specimens, and products of conception. DNA is composed of subunits called base pairs, with a person's DNA encoded in 6 billion such base pairs.
Although most of the DNA within all of us is very similar, there is sufficient variability to make each of us unique. This genetic variability is inherited and forms the basis for DNA profiling useful not only in identifying the perpetrators of crimes but also in establishing parentage (paternity and maternity) and other family relationships.
