UBC unveils DNA cleaner
New tool uses electricity to separate samples from impurities
A new tool that wipes dirt and contaminants out of DNA samples could revolutionize the way police investigate serious crime and terrorism, and help researchers find the root of disease.
The device, developed at the University of B.C. and now in some powerful hands, uses electricity to separate contaminants from DNA samples that once would have been unusable.
Early prototypes of the instrument, called Aurora, have been sold to a U.S. defence company, the U.S. navy and Canadian universities.
“There’s an enormous bottleneck right now in DNA extraction and analysis,” said Andre Marziali, director of UBC’s engineering physics department and Boreal Genomics, who led a research team in the creation of the tool.
“I’ve been to conferences recently where there have been talks from FBI and CIA members who point to DNA extraction as the toughest part of the [investigative] process.”
Too often, investigators are faced with large samples of evidence, but the DNA is too minuscule or drowning in dirt and molecules that intrude on its purity, rendering it worthless for forensic or health research.
One U. K. study found that one-third of all forensic case work failed because DNA samples were unusable, he said.
The research team, which includes scientists from UBC and BC Cancer Agency’s Genome Science Centre, published its findings in the scientific journal Proceedings of the National Academy of Science.
On police thrillers such as CSI, the bad guy leaves a coffee cup or a cigarette butt behind, and the case is closed.
In reality, DNA samples are often ruined by tissue dyes, ground soil, dust, smoke and other small particles.
The team used physics rather than chemistry to separate a DNA sample from its dirt, Marziali said.
Working with Aurora is simple enough: A researcher places the sample inside the machine, which “looks like a big white bread box.”
Within two hours, an electric charge has separated pure DNA from the “dirt” that surrounds it.
DNA responds differently to electrical charges than other molecules do, so the electricity separates the DNA from the molecules that scientists don’t need, Marziali said.
“Some [researchers] have used chemicals which have the same properties as DNA, so we’ve used physics where others have used chemistry.”
Tests using Aurora have so far proven successful.
When RCMP offered Marziali blue jeans stained with blood, Aurora was able to separate the jeans’ indigo dye from the DNA and pull out a pure DNA sample.
Used on organisms growing in the Alberta oilsands, the device showed how bacteria have evolved in the soil.
Marziali said it could be useful for clinical research, to detect HIV or target tumour markers — “any case where you have a needle in a haystack problem.”
It could be used to investigate bacteria in soil or detect listeria, E.coli or other contaminants in food, he said.
Isolating DNA from dense dust and other particles could also help researchers identify ancient skeletons and detect dangerous substances such as anthrax in the air in public places like subway stations.
At $50,000 each, prototypes have been sold to the U.S. navy, a U.S. defence contractor, the BC Cancer Agency, the University of Waterloo and McGill University in Montreal.
Locally, it has gone from the biophysics department to the university’s bureau of legal dentistry laboratory, where more research could help make it an everyday tool for forensics investigators.