What is DNA fingerprinting?

The term DNA fingerprinting, started to enter the English language following the accidental discovery of DNA profiling by the Dr Alec Jeffries at Leicester University (England) in the late 80's. DNA fingerprinting commonly refers to the practice of applying DNA techniques to help in the investigation and detection of crime.

DNA Fingerprinting generally refers to the process of producing a DNA profile from material left at a scene of a crime, for comparison against a DNA profile produced from a suspect. Given the power of this particular type of test, for discriminating

between individuals, the media have coined the term DNA fingerprinting, as a method for expressing the similarity of this technique to that of traditional fingerprint identification.

The actual process of producing a DNA fingerprint varies depending on the techniques being used, which is often influenced by a number of factors, including:

• The expertise within the laboratory
• Government legislation which may require compatibility with National DNA databases
• The level of funding available (a single DNA sequencer starts at $200,000)
• The level of discrimination required (very high for both paternity testing, and testing in criminal cases)
• The Quality standards being operated, and compliance to any legal requirements, that may be relevant

The most common DNA techniques used in the production of a DNA fingerprint is that of RFLP (restriction fragment length polymorphism) and PCR (polymerase chain reaction). Both exploit the fact that there are regions within ones DNA, which repeat themselves a number of times. The number of repeats is highly variable from one individual to another and can be measured by both techniques.

This variation gives rise to near unique DNA patterns generated from biological material recovered at a scene of a crime, to be compared against reference material provided by both victim and suspect.