ECU physicist to develop method for cancer cell detection
(Oct. 4, 2005)
An East Carolina University physicist has developed a laser beam and spectroscope technique that could someday help medical researchers detect and diagnose cancer cells. ECU physicist Yong-qing Li calls the technique Raman tweezers and says the technology can isolate and identify live cells using an infrared laser.
“The long-term goal of this project is to rapidly characterize and differentiate normal, pre-malignant, and tumor cells in humans at single-cell level,” Li said. Locating abnormalities in chromosomes, particularly in previously uncharacterized aspects of chromosomes, are also part of the long-term project.
A $24,000 grant from ECU’s Division of Research and Graduate Studies will enable Li and ECU biologist Thomas McConnell to collaborate with colleagues in the Brody School of Medicine to develop an instrument that combines the functions of a Raman spectrometer and the image forming abilities of a microscopy. This project will modify the spectrometer to identify normal and cancerous cells, Li said, and to obtain preliminary data about the cells.
Li and McConnell are working with John Wiley, professor of pediatrics, and Ted Bertrand, professor of microbiology and immunology, to develop the specialized instrument and to identify relevant cancer cell properties. Li is hopeful the work accomplished with this grant will provide an opportunity to further the long-term goals of the project.
Li, in collaboration with physicist Mumtaz Dinno, developed the infrared laser Raman-tweezers technique in 1999, which enables him to “trap” a cell in a laser beam. Using an infrared laser beam and a Raman spectrometer, Li has used the tweezers to instantly isolate and identify live cells from blood, yeast and bacteria. The infrared light, considered to be a gentler light beam, enables the trapped cell to remain live and undamaged as it is surveyed.
The process Li developed measures the light scattered as the laser beam passes through a live cell. Since each kind of cell is unique, the vibration it emits as light shines through it is also unique. The refracted light as it shines through the cell can be measured by a spectrometer which is part of the apparatus. The measurement is then compared to a database of the properties of known cells and can thus be identified, Li said.