Threshold densities of IAV particles binding to receptor
gradients
observed for different chip layouts and biotin densities. (a) Mean
threshold receptor density for corrals of different sizes on gradients
from 0.5% biotin-DOPE, determined for 24, 11, and 4 corrals. Error
bars indicate 95% confidence interval. n.s.: not significant, *: p < 0.05. (b) Mean threshold receptor density on gradients
prepared from different percentages of biotin-DOPE in 100 μm
corrals, determined for 36, 24, and 46 corrals. Error bars indicate
95% confidence interval. ***: p < 0.001. (c) Mean
threshold receptor density on 0.3% biotin-DOPE in 100 μm corrals
for different positions in the microchannel (A–C, Figure 1a), determined for
8, 6, and 8 corrals. Gradients in A and C are with the direction of
the flow through the channel; B is against the flow. Error bars indicate
95% confidence interval. n.s.: not significant. (d) Median lateral
intensity profiles of SAv on gradients prepared from different percentages
of biotin-DOPE in a 100 μm corral, without the edges removed
from the image. (e) Median lateral intensity profiles
of SAv (green) and ATTO 565-biotin (red) fluorescence on 0.5% biotin-DOPE
over four 100 μm corrals, normalized to the average of the first
and last 20 points of the median.