. The investigators propose to develop a system for rapid detection and accurate quantification of nucleic acids. They believe that their method could be used by many molecular biology labs for routine measurement of oligonucleotide, plasmids, total RNA, mRNA, or genomic DNA and may also prove useful for the diagnosis of human disease by the detection of specific genes by hybridization. The major component of this system is a detection module based on a very sensitive magnetic field sensor on a solid state chip. The amount of nucleic acid is determined by measuring the magnetic field generated by probes bound to the nucleic acid. In Phase I studies the investigators will test the limits of our prototype detection system by using magnetic colloids to measure the concentration of various nucleic acid samples. Their goal will be to reliably detect one nanogram of nucleic acid in a sample volume of one microliter. They will also test the feasibility of using their system to detect the hybridization of a specific oligonucleotide to a target gene using magnetic probes. PROPOSED COMMERCIAL APPLICATION: The proposed device, given competitive price and time per assay, would fulfill an important niche in nucleic acid measurements that does not have a competitive device at present. Maintaining a low instrument cost and large dynamic range of response would make it obtainable by most molecular biology laboratories, thereby greatly enhancing its commercial potential.