DNA profiling
![Variations of VNTR allele lengths in 6 individuals.](/Images/godic/202501/12/D1S80Demo5241.png")
![Alec Jeffreys, the pioneer of DNA profiling.](/Images/godic/202501/12/Alec_Jeffreys_-20085241.jpg")
![1: A cell sample is taken- usually a cheek swab or blood test
2: DNA is extracted from sample
3: Cleavage of DNA by restriction enzyme- the DNA is broken into small fragments
4: Small fragments are amplified by the Polymerase Chain Reaction- results in many
more fragments
5: DNA fragments are separated by electrophoresis
6: The fragments are transferred to an agar plate
7: On the Agar Plate specific DNA fragments are bound to a radioactive DNA probe
8: The Agar Plate is washed free of excess probe
9: An x-ray film is used to detect a radioactive pattern
10: The DNA is compared to other DNA samples](/Images/godic/202501/12/Stages_of_Gene_Fingerprinting.svg5241.png")
![CBP chemist reads a DNA profile to determine the origin of a commodity.](/Images/godic/202501/12/CBP_chemist_reads_a_DNA_profile5241.jpg")
DNA profiling (also called DNA fingerprinting, DNA testing, or DNA typing) is a forensic technique used to identify individuals by characteristics of their DNA. A DNA profile is a small set of DNA variations that is very likely to be different in all unrelated individuals, thereby being as unique to individuals as are fingerprints (hence the alternate name for the technique). DNA profiling should not be confused with full genome sequencing. First developed and used in 1985, DNA profiling is used in, for example, parentage testing and criminal investigation, to identify a person or to place a person at a crime scene, techniques which are now employed globally in forensic science to facilitate police detective work and help clarify paternity and immigration disputes.