DNA Microarray Technique Could Revolutionize Medical Diagnostics

The dream of personalized medicine—in which diagnostics, risk predictions and treatment decisions are based on a patient’s genetic profile — may be on the verge of being expanded beyond the wealthiest of nations with state-of-the-art clinics. A team of researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has invented a technique in which DNA or RNA assays—the key to genetic profiling and disease detection—can be read and evaluated without the need of elaborate chemical labeling or sophisticated instrumentation. Based on electrostatic repulsion—in which objects with the same electrical charge repel one another—the technique is relatively simple and inexpensive to implement, and can be carried out in a matter of minutes.

“One of the most amazing things about our electrostatic detection method is that it requires nothing more than the naked eye to read out results that currently require chemical labeling and confocal laser scanners,” said Jay Groves, a chemist with joint appointments at Berkeley Lab’s Physical Biosciences Division and the Chemistry Department of the University of California (UC) at Berkeley, who led this research. “We believe this technique could revolutionize the use of DNA microarrays for both research and diagnostics.”

Groves, who is also a Howard Hughes Medical Institute (HHMI) investigator, and members of his research group Nathan Clack and Khalid Salaita, have published a paper on their technique in the journal Nature Biotechnology, which is now available online. The paper is entitled “Electrostatic readout of DNA microarrays with charged microspheres.”

In their paper, Groves, Clack, and Salaita describe how dispersing a fluid containing thousands of electrically-charged microscopic beads or spheres made of silica (glass) across the surface of a DNA microarray and then observing the Brownian motion of the spheres provides measurements of the electrical charges of the DNA molecules. These measurements can in turn be used to interrogate millions of DNA sequences at a time. What’s more, these measurements can be observed and recorded with a simple hand-held imaging device—even a cell phone camera will do.

Release date: June 30, 2008
Source: Lawrence Berkeley National Laboratory