Now, device to simplify human DNA extraction

Scientists have developed a new hand-held device that can extract human DNA from a swab of saliva and make it ready for analysis and genome sequencing within minutes.
University of Washington engineers and NanoFacture, a company in Bellevue, Washington, have created a device that can extract human deoxyribonucleic acid (DNA) from fluid samples in a simpler, more efficient and environmentally friendly way than conventional methods.
The device will give hospitals and research labs a much easier way to separate DNA from human fluid samples, which will help with genome sequencing, disease diagnosis and forensic investigations.
"It's very complex to extract DNA. When you think of the current procedure, the equivalent is like collecting human hair using a construction crane," said Jae-Hyun Chung, a UW associate professor of mechanical engineering who led the research.

Separating DNA from bodily fluids is a cumbersome process that's become a bottleneck as scientists make advances in genome sequencing, particularly for disease prevention and treatment.
Conventional methods use a centrifuge to spin and separate DNA molecules or strain them from a fluid sample with a micro-filter, but these processes take 20 to 30 minutes to complete and can require excessive toxic chemicals.

UW engineers designed microscopic probes that dip into a fluid sample - saliva, sputum or blood - and apply an electric field within the liquid.
That draws particles to concentrate around the surface of the tiny probe. Larger particles hit the tip and swerve away, but DNA-sized molecules stick to the probe and are trapped on the surface. It takes two or three minutes to separate and purify DNA using this technology.

"This simple process removes all the steps of conventional methods," Chung said.
The hand-held device can clean four separate human fluid samples at once, but the technology can be scaled up to prepare 96 samples at a time, which is standard for large-scale handling.
The tiny probes, called microtips and nanotips, were designed and built at the UW in a micro-fabrication facility where a technician can make up to 1 million tips in a year, which is key in proving that large-scale production is feasible, Chung said.
Engineers in Chung's lab also have designed a pencil-sized device using the same probe technology that could be sent home with patients or distributed to those serving in the military overseas.