DNA hybridization using "Bead-Array": Probe-attached beads arrayed in a capillary in a predetermined order

We present a DNA analysis device called "Bead-Array", in which DNA-probe-attached beads (100 Urn) are arrayed in a capillary in a predetermined order. We developed this device to overcome the problems of using DNA microarray technol-ogy, including high cost and a lengthy analysis time. Bead-arrays can easily be mass-produced even for many different probe combinations, and their small reaction volume and the use of sample flows enables faster hybridization. To demonstra-te this, we examined DNA hybridization experi-ments using 18-mer DNA probes and targets and compared them to ones with beads in tubes. The results show that hybridization in bead-arrays progresses more than 100 times faster and reach the plateau in less than three min. These fea-tures suggest that the bead-array particularly meets the need for high-speed and disposable devices, for example diagnosis devices