Supplementary Figure 3: Binding behavior of phage bearing WT pertuzumab or SG mutant, as single-chain Fv fragments (scFvs).

Phage-displayed scFvs (WT or SG mutant) were analyzed for binding to HER2-ECD at pH 7.4 and 5.8 using ELISA. The ratio of signal measured at pH 7.4 to pH 5.8 was calculated. The data shown is the mean ratio of a total of 6 independent samples ± SD for each phage type/pH derived from two independent experiments.