Microarray-Based Hybridization Technology for Biosensors

Current DNA-microarray technologies for detecting specific mutations are challenged in discriminating multiple base-pair (bp) changes in DNA sequences that are more than 50 base pairs in length. To overcome this limitation we will develop a novel microarray-based hybridization technology that exploits the homologous pairing of DNA strands driven by the RecA strand-exchange protein of E. coli. Using magnetic torque-induced dissociation of surface- immobilized RecA-DNA complexes conjugated to magnetic nanoparticles, we will establish the use of magnetic-field- dependent strand-association isotherms as a sensitive method for discriminating hybridization of motifs an order of magnitude longer than those accessible using current technology. These studies have significant potential impact on problems related to biological sensors and their applications in molecular genomics and pathogen characterization.