Figure 3. Identification of the binding selectivity of the 18 clones by cellular ELISA.

Phage clones binding to CHO-K1/VPAC1 cells (blue bars) and wild-type CHO-K1 cells (red bars) were detected by the HRP-conjugated anti-M13 phage antibody. PBS and URps (unrelated phage, an amplified phage randomly selected from the original phage peptide library) were used as negative controls. Triplicate determinations were done at each data point, and average OD_{450 nm} of two types of cells are shown. Single asterisk denotes p<0.01(OD_{450 nm} of each clone binding to CHO-K1/VPAC1 cells versus CHO-K1 cells).