Figure 2

Analysis of the lane variation using the streptavidin-biotin affinity reaction. A microfluidic chamber with the same design and dimensions as described in Figure 1, but etched into a silicon chip and closed by bonding, was coated with streptavidin. Fluorescein-labeled biotin was then hydrodynamically guided in 50-μm-wide lanes over an area of 1000 × 1000 μm (arrows indicate the directions of flow). Ten lanes were applied evenly, and the procedure was repeated in a perpendicular direction, resulting in a grid of 100 intersections. The bended shape of the lanes in the lower and left part of the photomicrograph resulted from the hydrodynamic bending of the flow due to the quadratic shape of the microfluidic chamber. Scale bar, 100 μm.