Fig 1. pH-dependent binding of F0016 mAbs to FcRn as assessed by ELISA at pH 6.0 (circles) and pH 7.4 (squares).

First, 96-well plates were coated with 10 μg/mL streptavidin overnight at 4°C. Biotinylated FcRn was added at 250 ng/mL and incubated for 1 h at 37°C. Serially diluted F0016 mAbs were added and incubated for 1 h at 37°C, and then the plates were washed with PBST at pH 6.0 or 7.4, respectively. Following incubation with HRP-conjugated goat anti-human IgG (H+L) antibody for 1 h at 37°C, the plates were washed again with PBST at pH 6.0 or 7.4, respectively. The binding curves of F0016 Abs to FcRn were analyzed using a four-parameter logistic fit regression model. Results were shown as mean ± SD (error bars, n = 2).