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Portable device shows promise for rapid oral cancer testingScientists supported by the National Institute of Dental and Craniofacial Research have engineered what they call the first fully automated, all-in-one "lab on a chip" test that can be programmed to identify a common sign of oral cancer in cells brushed from the mouth. About half the size of a toaster, the portable device yields results in just under 10 minutes, according to an NIDCR news release. "What's exciting is the speed and efficiency that this test will bring to the diagnostic process," said John McDevitt, Ph.D., a scientist at the University of Texas at Austin. "Patients will get immediate results and feedback from their dentist or doctor on how best to proceed." According to the Texas team, their proof of principle study showed that their test could accurately measure levels of epidermal growth factor receptor (EGFR) on three distinct types of oral cancer cells. This protein, which is normally displayed on the surface of cells, tends to be overproduced in oral tumor cells and serves as a measurable marker of oral cancer. The testing process using the device begins with brushing cells from a suspicious lesion, suspending them in fluid, and loading a drop of the mixture into the device. When activated, the device conveys the fluid down a tiny, microfluidic channel to a chamber with a porous membrane. "The cells stick to the membrane floor like starfish in a net," said Shannon Weigum, a member of the Texas team. "The floor has little exit holes that drain the fluid out of the chamber and allow us to pump in a cocktail of, in this case, antibodies that are tagged with a fluorescent dye and that are programmed to seek out and attach to the EGFR displayed on the cells." The fluorescent tags are then viewed on a computer screen to determine how much EGFR is present on the cell surface. The scientists reported that their lab-on-a-chip protocol took about nine minutes to complete, from sample collection to digital display. According to Dr. McDevitt, the group's next step is to program the device to read not just EGFR levels but those of other proteins and genes that, when altered, are indicative of a developing oral tumor.
©2008 American Dental Association. All rights reserved. Reproduction or republication is strictly prohibited without the prior written permission from the American Dental Association. 8/27/07 |
