Their device can be contained on a single chip and is simple and inexpensive to manufacture. "The idea would be that doctors could take a tiny drop of blood from patients and be able to run diagnostic tests on it right there in their office, instead of sending it away to a lab where testing can take days and is expensive," said Weihua Guan, a Yale engineering graduate student who led the project.
In addition to diagnostics, this "lab-on-a-chip" would have a wide range of applications, Guan said, such as being able to analyze how individual cells respond to different stimulation. While there are several other techniques for cell-manipulation available now, such as optical tweezers, the Yale team's approach actually works better as the size of the targets gets smaller, contrary to other approaches.
The team, whose findings appear in the May 23 Early Edition of the Proceedings of the National Academy of Sciences, used charged polystyrene beads rather than actual DNA molecules, along with a two-dimensional trap to prove that the technique worked. Next, they will work toward creating a 3-D trap using DNA molecules, which, at two nanometers, are even smaller than the test beads. They hope to have a working, 3-D trap using DNA molecules in the next year or two. The project is funded by a National Institutes of Health program that aims to sequence a patient's entire genome for less than $1,000.
"This is the future of personalized medicine," Guan said.
Weihua Guan and Mark Reed confine a single polystyrene bead to an accuracy of just 10 nanometers, or about 1/10,000th the width of a human hair.
(Photo Credit: Weihua Guan and Mark Reed/Yale University)
Scientists were able to trap a single particle between four microelectrodes, paving the way for a faster and cheaper way to sequence DNA.
(Photo Credit: Weihua Guan and Mark Reed/Yale University)
Source: Yale University