DNA fingerprinting is a laboratory technique used to establish a link between biological evidence and a suspect in a criminal investigation. A DNA sample taken from a crime scene is compared with a DNA sample from a suspect. If the two DNA profiles are a match, then the evidence came from that suspect. Conversely, if the two DNA profiles do not match, then the evidence cannot have come from the suspect. DNA fingerprinting is also used to establish paternity.
There are various methods for analyzing DNA to establish if two samples are the same or different. This is sometimes referred to as DNA fingerprinting. For example, two cloned pieces of DNA can be studied in the laboratory to determine if they have portions in common, and thus overlap with one another. In a different setting, such as a crime scene, DNA samples can be collected and analyzed to determine if they match DNA samples obtained from suspects of that crime. If two DNA samples have the same fingerprint, then there is a very high statistical likelihood that they came from the same person. Such an approach can also be used to establish paternity.Eric D. Green, M.D., Ph.D.