Figure 7.

Binding of IgG variants to neonatal Fc receptor (FcRn). In a competition binding format, titrating amounts of antibody were combined with a fixed concentration (4 μg/mL) of biotin-labeled huIgG1. Antibody mixtures were incubated with immobilized human FcRn on a plate for 1 h, washed, detected with streptavidin-horseradish peroxidase (HRP), and developed with tetramethylbenzidine (TMB) substrate. Bound tracer antibody was detected via absorbance at 450 nm measured on a plate reader. (A) Ab1 samples and (B) Ab2 samples were tested in duplicate and error bars represent mean ± range.