Ballast water is a necessary component of the shipping industry where it is employed for weight balancing. Unfortunately, such water has been implicated as one of the chief means of aquatic invasive species introduction worldwide. Consequently, the rapid genetic identification of organisms within a ballast water sample is of interest. Traditionally, genetic identification is accomplished using conventional microarray technology. Such technology is attractive in its ability to offer large oligomer library scans. However, the existence of large diffusion distances between target DNA and probe DNA results in lengthy assay times, making these microarrays impractical for rapid identification purposes.

Recently, significant attention has been given to developing a microfluidic chip that can be utilized for conducting DNA-DNA hybridization studies. We report here on the development of a novel microfluidic chip that employs a genetic bead hybridization platform. This chip has been fabricated such that oligomer functionalized beads are packed within a miniature hybridization chamber. This packing is accomplished through the fabrication of porous filters embedded within the microchannels that are connected to the hybridization chamber. Heat-denatured DNA is then passed through the microchannels and into the genetic bead packed bed region. The implementation of this genetic bead packed bed region is advantageous in that the target DNA is brought into close contact with the oligomers on the surface of the beads. Additionally, the surface area available for hybridization is greatly increased. Finally, the detection of positive hybridization is accomplished through fluorescence.