Dna fingerprinting why is it important

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. In , Alec Jeffreys not yet a Professor or Sir was one of the first to apply the emerging science of genomics to the study of inherited variation in human DNA, discovering a type of variation, termed RFLPs, that result from alterations in single bases in our DNA.

He showed that these are abundant - we now know that there are about 10,, different sites at which people can vary in their DNA sequence. Professor Jeffreys went on to show that some regions of human DNA are far more variable than these sites of single base variation.

These regions, termed minisatellites, show the curious property of being stuttered, with variation resulting from individual differences in the number of stutters.

This work led, almost accidentally, to the development in of DNA fingerprinting. Professor Jeffreys demonstrated that a single test could in principle distinguish everyone on the face of the planet except for identical twins. The subsequent impact that DNA fingerprinting has had on individual identification in criminal investigations and in legal medicine has been dramatic and remains as one of the most well known applications of human molecular genetics. The origin of all this inherited variation in human DNA remains the focus of Jeffreys' research.

Variation ultimately arises from two processes. It was first developed in the s. These techniques have revolutionised the way that the police solve crimes. If you have any other comments or suggestions, please let us know at comment yourgenome. Can you spare minutes to tell us what you think of this website? Open survey. In: Facts Methods and Technology. Background Almost every cell in our body contains our DNA. On average, about The remaining percentage is what makes us unique unless you are an identical twin!

Although this might sound like a small amount, it means that there are around three million base pairs that are different between two people. These differences can be compared and used to help distinguish you from someone else. Minisatellites are short sequences base pairs long of repetitive DNA that show greater variation from one person to the next than other parts of the genome.

The first minisatellite was discovered in When first described in by British scientist Alec Jeffreys, the technique focused on sequences of DNA called mini-satellites that contained repeating patterns with no known function. These sequences are unique to each individual, with the exception of identical twins. The odds of identifying an individual correctly depends on the number of repeating sequences tested and their size.

For human testing, subjects typically are asked for a DNA sample, which can be supplied as a blood sample or as a swab of tissue from inside the mouth. Patients often prefer mouth swabs because the method is less invasive, but it has a few drawbacks. If samples are not stored quickly and properly, bacteria can attack the cells containing DNA, reducing the accuracy of the results.

Another issue is that cells are not visible, so there is no guarantee that DNA will be present after a swab. The DNA is replicated, amplified, cut and separated through these and other processes to achieve a more thorough profile fingerprint to compare to the other samples. Genetic fingerprinting can be used in criminal forensic investigations.

A very small quantity of DNA is reliable enough in identifying individuals involved in a crime. Similarly, DNA fingerprinting can and does exonerate innocent people of crimes—sometimes even crimes committed years ago. DNA fingerprinting can also be used to identify a decomposing body. DNA fingerprinting can answer the question of the relationship to another person quickly and accurately.