DNA paternity testing is a complex scientific process, carried out on a simple mouth swab, which can positively identify relationships between people. Most commonly it is used to establish if a man is the true biological father of a child.

DNA paternity testing is also often referred to simply as a DNA test, a paternity test or DNA testing. It was developed by Sir Alec Jeffreys at the University of Leicester in 1985. Cellmark became the UK's first private DNA paternity testing laboratory in 1987.

DNA (Deoxyribonucleic Acid) is the body’s genetic 'blueprint'. It is a long thread-like molecule which carries the "genetic code" that determines our individual characteristics. DNA is found in almost all of the billions of cells that make up our body. Every child inherits a unique mixture of DNA from its parents so, except for identical twins, no two people in the world have exactly the same genetic code.