The DNA sequence data generated by the Human Genome Project continues to revolutionize the field of medicine by uncovering the genetic basis for many diseases. Unfortunately, the considerable expense associated with the purchase and operation of specialized equipment and the requirement of a dedicated laboratory infrastructure staffed by highly trained personnel currently renders sequencing impractical for use in routine medical practice. Microfabricated sequencing devices are poised to offer an inexpensive alternative to conventional equipment, ultimately making direct genomic sequencing practical for use as a true point-of-care diagnostic protocol. It addition, moving to the microdevice format substantially reduces the sample volumes required for analysis (to the order of nanoliters) and introduces the ability to fabricate self-contained portable sequencing devices which can be easily deployed in remote field locations for a variety of applications, including the rapid identification and tracking of infectious diseases. A key element of any sequencing device is the ability to perform size-based separations of DNA fragments using electrophoresis. Complete sequencing requires sufficient resolution to distinguish fragments which differ by only one base pair in length in fragments approaching 1,000 base pairs in total length - a requirement that is routinely met by conventional slab gel and capillary electrophoresis systems. At the present time, separation channel lengths on the order of several centimeters are required to achieve single base pair resolution in microfabricated electrophoresis systems. Though impressive, the size of current generation microfabricated sequencing devices is still too large to exploit more than a fraction of the enormous cost savings possible through mass production via photolithographic fabrication techniques. These techniques, routinely employed in the semiconductor industry, allow tens or hundreds of devices to be produced on a single wafer.
The specific aim of this research project is to demonstrate that microdevice-based electrophoretic separations can achieve resolution comparable to conventional macro-scale DNA analysis systems over length scales on the order of one centimeter or less. The Genome Scholar Development and Faculty Transition Award will provide the opportunity to obtain training in the key areas of microfabrication techniques and molecular biology methods in order to meet this research objective.
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