A device created by a collaborative team of engineers and scientists at the University of Arizona may significantly reduce the amount of time necessary to diagnose tissue infections. The technology’s novel approach to molecular diagnostics, called DOTS qPCR, is faster, more efficient, and less expensive than options currently being used in clinics.
DOTS qPCR, invented by Jeong-Yeol Yoon, a professor in the Department of Agricultural and Biosystems Engineering, and his research group, stands for droplet-on-thermocouple silhouette real-time PCR (polymerase chain reaction).
The technology measures subtle surface tension changes at the interface of a water droplet suspended in an oil medium. The water droplet, which contains the target DNA to be amplified, is moved along a heat gradient in the oil to begin the chain reaction. As more copies of the target DNA are produced, they move toward the oil-water interface, resulting in detectable changes in surface tension.
The size of the droplet can be measured using a smartphone camera, providing a method to observe the course of the reaction in real time.
"With DOTS qPCR, we are able to detect amplification and identify the infection after as few as four thermal cycles, while other methods are working with between 18 and 30," said Yoon.
In addition to much faster diagnosis times, the system does not require samples to be completely free of other contaminants.