Magnetoresistive biochips

Abstract

fuJ.; a) Conventional hybridisation detection using fluorescent labels attached to biological targets, and an external laser-based fluorescent scanner for detection. b) magneto resistive-based hybridization detection using magnetic labels,and an integrated magnetoresistive sensor array for detection. patient samples, the detection scheme must lead not only to the knowledge of the presence of the particular gene (Yes or No) but also to a quantitative analysis (present in what percentage). For Single Nucleotide Polymorphism chips (SNP), where single DNA base pair changes are being identified, the simple (Yes or No) answer is sufficient. In both cases, the chip should be able to discriminate against false positives (non-specifically bound molecules). A recent example of this technology are DNA microarray chips fabricated by Nanogen [3], where charged target biomolecules are moved over immobilized probes. Electric fields are used for hybridization enhancement and stringency control.