For Immediate Release: February [INSERT], 2006
Contact: Kira Edler, 617-358-1240,
Boston University scientists develop newapplication tocharacterize structure of dna molecules
New technique provides insight into how DNA conforms to microarray surfaces
(Boston) —A team of researchers from Boston University has developeda new application called high-resolution spectral self-interference fluorescence microscopy (SSFM) allowing for precise measurement of the average location of a fluorescent label in a DNA layer relative to the surface and thus determine specific information on the conformation of the surface-bound DNA molecules.to further characterize the structure of DNA molecules. According to their study, published in the current issue ofProceedings of the National Academy of Sciences, the new technique provides insight into the shape of DNA molecules bound to athe surface such as in of a microarray. Determining the conformation of DNA molecules attached to microarray surfaces maysignificantly improvethe efficiency of DNAhybridization and microarray technology thus impact emerging clinical and biotechnological fields.
The new SSFM technique, using a grating spectrometer, maps theinterference spectrum emissions from a fluorophore (fluorescent particlemolecule) located on a layered reflecting surface into a preciseposition. Using a grating spectrometer, the observed, or interference spectrum, combines both direct and reflected light emissions from the fluorophores. This provides information about the location and position of the fluorophore labels, and hence the surface to which they are attached, with sub-nanometer accuracy.
“Although a number of other methods have been used to determine the structure of the DNA layer, they are not very sensitive to variations in the shape of DNA molecules,” said Bennett Goldberg, professor and chairof the Department of Physics at BU and one of the study co-authors. “Our group has developed spectral self-interference fluorescence microscopyto determine the precise measurement of the average location of a fluorescent label in a DNA layer relative to the surface in orderto obtain specific information about the conformation of the DNAmolecules.”
Using SSFM,the team estimated the shape of coiled single-stranded DNA, the average tilt of double-stranded DNA of different lengths, and estimated the amount of hybridization. The data provide important new proof points for the capabilities of novel optical surface analysis methods of the disposition of DNA on microarray surfaces.
“The determination of DNA conformations and hybridization behavior provide information required to move DNA interfacial applications forward and thus impact emerging clinical and biotechnological fields,” said M. Selim Unlu, electrical and computer engineering professor and study
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BostonUniversity
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co-author. “Our research shows that locating a fluorescent label attached to a certain position within a DNA chain offers precise information about the shape of DNA molecules bound to the surface of a microarray.”
Additional study investigators include Lev Moiseev, PhD in Biology at BU and electrical and computer engineering research associate, Anna K. Swan, electrical and computer engineering associate professor, and Charles R. Cantor,biomedical engineering professor and co-directorof the Center for Advanced Biotechnology at BU.
Founded in 1839, BostonUniversity is an internationally recognized institution of higher education and research. With more than 30,000 students, it is the fourth largest independent university in the United States. BU contains 17 colleges and schools along with a number of multi-disciplinary centers and institutes which are central to the school’s research and teaching mission.
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