Expression and selection of the yeast display CH2 domain library. (A) The grafted CH2 yeast library indicated 43% of expressed cell. In contrast, the grafted VH yeast library indicated ~20% of expressed cell. (B) The sorting rounds of CH2 yeast library against nucleolin. The double-positive yeast cells were selected from sort gates. Four figures shows sorting of yeast library against nucleolin at rounds 1,2,3, and 4. (C) Binding of yeast-expressed CH2 binders to antigens. Three antigens nucleolin, folate receptor b, and mesothelin, were used to detect CH2 binders.