Fig. 3: Enhancement of protein-detection efficiency by narrow microchannel comparable to laser spot.
From: Attogram-level light-induced antigen-antibody binding confined in microflow
a Optical transmission image of a wide microchannel (350 μm × 100 μm) and b protein concentration dependence of the ratio of the black area representing the assembled structure of the probe beads and CD9/CD63 fusion protein; laser focusing position is adjusted to 65 μm below the bottom of the microchannel and the spot diameter at the bottom is expanded to 68.3 μm (orange circle). c Optical transmission image of a narrow microchannel (100 μm × 100 μm) and d protein concentration dependence of the ratio of the black area representing the assembled structure of the modified CD9/CD63 fusion protein and probe beads modified with anti-CD63 antibody, where the (laser focusing position and spot diameter correspond to those in a and b; the size of the orange circle is the same as in a). In b and d, error bars indicate standard deviation. Individual data points are shown as small plots.
