PITTSBURGHCarnegie Mellon University scientists have married bright fluorescent dye molecules with DNA nanostructure templates to make nanosized fluorescent labels that hold considerable promise for studying fundamental chemical and biochemical reactions in single molecules or cells. The work, published online Jan. 26 in "The Journal of the American Chemical Society, improves the sensitivity for fluorescence-based imaging and medical diagnostics.
"Our DNA nanotags offer unprecedented densities of fluorescent dyes and, thus, the potential for extremely bright fluorescent labels, said graduate student Andrea Benvin, who developed the nanotags in the laboratory of Bruce Armitage, associate professor of chemistry in the Mellon College of Science (MCS) at Carnegie Mellon. "Weve put it all into a very small package, which will allow us to detect molecules with great sensitivity without interfering with the biological processes we are trying to understand."
The high brightness of the nanotags should be of great help in detecting rare cancer cells within tissue biopsies, for example, which is important in determining whether treatments have been successful or if recurrence is likely, according to Armitage. In addition, DNA nanotags offer the opportunity to perform multicolor experiments. This feature is extremely useful for imaging applications, Armitage says, because the multiple colors can be seen simultaneously, requiring only one experiment using one laser and one fluorescence-imaging machine.
"For example, two different populations of cells, one healthy and the other cancerous, could be distinguished based on labeling them with different color fluorescent nanotags," Armitage said.
Benvin, Armitage and colleagues at Carnegie Mellons Molecular Biosensor and Imaging Center modeled their DNA nanotags on the structure of phycobiliproteins. Found in certain types of algae, such as the red and blue algae in fresh and marine waters,
Contact: Lauren Ward
Carnegie Mellon University