A recirculating microfluidic device fabricated by laminating Mylar and glass was developed for the analysis of hybridization of oligonucleotides to DNA microarrays. The device is part of a system that provides controlled hybridization to DNA probes immobilized in a microarray of polyacrylamide gel pads using recirculation and temperature control. The system was used to obtain real-time kinetics of DNA hybridization and more accurate melting profiles of target-probe duplexes than possible using a static hybridization format. Recirculation shortened the time of perfect match target-probe hybridization from 6 hours to 2 hours and shifted the Td by 1.54 °C, relative to static conditions. The experimental results were consistent with a three-dimensional simulation of hybridization using a recirculating buffer system.