DOE Human Genome Program Contractor-Grantee Workshop VIII
February 27-March 2, 2000  Santa Fe, NM

147. Molecular Gates for Improved DNA Cleanup and Handling in Microfabricated Devices

Paul W. Bohn, T.C. Kuo, Wenju Feng, Lisa Sloan, and Jonathan V. Sweedler

Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801

bohn@scs.uiuc.edu

The development of integrated systems capable of automated accurate sequence generation from sample introduction to sequence output is an important goal of the DOE Human Genome Project. Microfabricated DNA analyzers (such as microfabricated PCR systems with integrated CE systems) have been developed that offer a number of important advantages compared to the traditional large scale methods. However, the actual interface between these microfabricated subassemblies can be problematic. For example, to obtain the highest quality sequencing results, sample cleanup is required after PCR reactions but before introducing the sample to a CE separation. We are developing unique integration technology based on "molecular gates." Molecular gates can be thought of as intelligent (externally controllable) adsorption membranes. The successful molecular gate has the ability to "capture" a preselected DNA band on-device after PCR analysis to allow sample cleanup, release the analyte for electrophoretic sequencing and even to capture a particular DNA band eluting from the separation channel for further characterization. This allows easier interfacing between the separate components of a total "lab-on-a-chip" sequencer. In the first year of this project, we have optimized molecular gate technology and are developing the protocols for high efficiency and fast sample capture and release. The ability to have the molecular gate discriminate against small molecules is important, and we are currently able to drive specific analyte classes into and out of the gate structure. The overall device will offer the ability to desalt and cleanup the DNA between the various subassemblies of an integrated DNA system. Current work involves integrating these devices into microfabricated electrophoresis system for improved sample cleanup capabilities.