- 3:15 PM

Microfluidic Device for Nucleic Acid Purification Based on Surface Adsorption to Colloidal Silica

Tyson Poeckh, Ronald G. Larson, and Michael J. Solomon. Chemical Engineering, University of Michigan, 3074 H.H. Dow, 2300 Hayward, Ann Arbor, MI 48109

Microfabricated lab-on-a-chip systems are ideal for rapid on-the-spot detection of bacterial or viral pathogens. For example, on-chip quantitative polymerase chain reaction (PCR) assays utilizing nanoliter-scale quantities of reagents and sample materials have been demonstrated. For a truly portable device, however, the entire upstream sample purification procedure would also need to be integrated. This would require the incorporation of a nucleic acid purification step prior to detection with the PCR. We describe efforts to adapt to a microchip format a standard nucleic acid purification technique based on the binding of nucleic acids to the surface of silica particles in the presence of a chaotropic salt solution. We demonstrate through experiments the relevant parameters to vary in designing such a nucleic acid purification microchip and how one would optimize such a device to provide nucleic acid of sufficient concentration and purity for PCR amplification. The feasibility of purifying RNA from a clinical sample, which is relevant for the detection of pathogens such as bird flu, is demonstrated.