What is DNA Testing?
DNA testing has a wide variety of uses and is most often used for medical research, paternity identification and crime forensics. Recently, the role of DNA testing has also expanded out to more common “consumer” uses such as having one's DNA tested for susceptibility to certain diseases or the presence or absence of genetic markers that define certain habits or help map out our ancestry.
Forensic science was one of the first users of DNA testing – spearheaded by the FBI in the 1980's. The purpose of forensics is to take DNA samples from a crime scene and to match those samples back with a suspect to prove their involvement in the crime or not. While DNA testing of crime scene samples does not prove that the sample came from the suspect (after all, it is easy to plant hairs or other samples that contain DNA at crime scenes to implicate others), it is more often used to prove that the sample did not come from a suspect. The most important area of forensic DNA analysis has been its powerful use in setting suspects free rather than convicting them. In recent years scores of people have been released from prison thanks to DNA analysis that was simply not available at the time they were incarcerated. One out of every three cases that go through the FBI labs has shown through DNA testing that the suspect in question could not have committed the crime. By eliminating suspects through the use of DNA it helps law enforcement single in on the true suspect.
DNA analysis involves the collection of a sample that contains DNA material. This often involves taking samples of hair (with roots attached), or swabbing the inside of the cheeks to collect cells. Only a very small sample of material is needed to collect usable DNA; this is due in part to the fact that every cell within the human body contains DNA. Crime scene investigators have been able to process DNA from single flakes of skin. It is the silent witness that can hold the information to what actually took place at a crime scene.
Fossil and skeletal analysis is another area where DNA testing is used. DNA resides in every cell inside the human body and therefore it is also present in our bones. Fossils of ancient people and animals have produced usable samples of DNA that have helped us not only better understand past generations and the evolution of life on our planet, but also have helped identify and classify species from ancient times. The remains of victims of crimes from over a century ago can be exhumed and tested to prove family heritage or genetic composition of the individual.
In modern day testing the Supreme Court of the United States has ruled that lower courts and law enforcement authorities may force a suspect to submit to a DNA test if reasonable evidence exists to place them at the scene of the crime. Many suspects voluntarily provide samples since DNA testing is the quickest, easiest way to prove innocence.
DNA testing has also been used in recent years to free suspects who have been jailed for crimes they did not commit. With the advances of DNA testing methodologies and procedures that were not available at the time of incarceration are now available that can prove their innocence. Some suspects who have been freed using DNA testing have literally been saved from death row by the efforts of lawyers and scientists.
In order to protect and identify children, many parents are now submitting samples of their children's DNA to testing laboratories so they may have a permanent record of their DNA should the need ever arise. Law enforcement organizations across the country consider DNA testing to be the next generation in fingerprinting with much higher accuracy and reliability.
Thanks to advancements in technology the cost for DNA testing has fallen to levels that it is becoming commonplace for use in a wide variety of applications. A common DNA test for paternity costs less than $150 in most areas and DNA matching tests can run as low as $300.