Cellular Genomic Analysis with GMR Sensor Arrays

A new cellular genomic analysis device is introduced that integrates cell lysing, microfluidics, and micromagnetic mRNA labeling and detection on one microfabricated substrate. The magnetic sensor, benzocyclobutene (BCB) microfluidics, investigative genomic assay, magnetic labels, and surface chemistry development for the new cellular genomic analysis device are described. mYWORDS: biosensor, genomics, GMR, magnetic labeling 1. INTRODUCTION A number of issues hinder the genomic analysis of heterogeneous mixtures of cells. For example, current gene array technologies perform poorly when screening a low cell population. This limitation becomes even more relevant when dealing with the quantification of very low mRNA copy numbers per cell [I]. We have previously developed a unique DNA hybridization detection system that relies on giant magnetoresistive (GMR) sensors [2,3]. This system, based on the detection of magnetic microbead labels, is capable of observing a single DNA hybridization event. We are now attempting to apply this technology to the detection of low concentrations of mRNA, ideally that from a single cell.