Forensic Science and DNA Fingerprinting Improvements

Ever since Sir Alec Jeffreys first invented DNA fingerprinting technology in the 1980s, thousands of criminals all over the world have been rumbled and sent to prison. However, the process does have its limitations. A major difficulty facing crime scene investigators and forensic teams is that it is almost impossible to be able to separate out the DNA from different individuals. For example, if several suspects handled a weapon. Their job is made that much harder if the samples are of poor quality.

But that is changing with the introduction of a technology known as DNAboost, which can separate DNA samples and provide identifiable DNA profiles from the biological material.

DNA fingerprinting works because there are a number of highly repetitive sequences in our DNA - short tandem repeat sequences (STRs). They are repeated over and over again and have been mapped to specific points on nearly all human chromosomes. An individual genetic profile is compiled from counting the number of repeats of a specific STR sequence at particular points. The Forensic Science Service (FSS) in the UK uses 11 points. The overall pattern is unique for each individual. However, as good as the technology is, it has been confounded by the presence of many samples at a crime scene. DNAboost claims to be able to create profiles from these mixed samples, although the company behind it is remaining tight-lipped about how it is achieved. What is widely known is that the technology uses a powerful algorithm, to separate mixed samples and experts are claiming that it could boost detection rates by as much as 30 per cent. Police forces are hopeful that it could help them crack thousands of cold cases that have yet to be solved.

There is opposition to this advance in DNA fingerprinting technology. Critics believe that the new software is not watertight and that potentially it could lead to miscarriages of justice. Prof Allan Jamieson, director of The Forensic Institute in Glasgow pointed out in an interview with the British Broadcasting Corporation (BBC) how DNAboost could cause confusion. “If I have profile AB and you have profile CD, our mixed cells would have a profile ABCD. However, the same profile could be produced by two people with profiles AC and BD, or AD and BC.”

DNAboost has been piloted by several police forces in the north of England and is being watched by forensic services in the US and other countries.

BBC News http://news.bbc.co.uk/mobile/bbc_news/sci_nature/795/79594/story7959431.shtml