Study on bead-based micro biochip and analytical system for protein detection

In this paper, proteins are purified and detected through bead-based bioassay on a silicon based micro biochip. Polystyrene micro beads pre-coated with specific capture molecules are packed into a microchip for a test. After binding target proteins, the proteins are re-separated from the beads using photolytic elution method. The photolytic elution method is enabled by introducing photo cleavable ligand on the beads. The purified target proteins are quantitatively detected using a fluorescence intensity measurement. The fluorescence measurements system is on-line coupled with the fabricated microchip. In fabrication, a silicon-on-glass structure is used so that a microchamber on microchip is transparent from the bottom to the top. Using this microchip, streptavidin is selectively purified and detected from low abundant protein mixture of human serum albumin, ovalbumin and streptavidin.