Comparative binding analysis of antibody displaying phages using whole cell ELISA. fUSE5-ZZ-chFRP5, fUSE5-ZZ-trastuzumab and control phages fUSE5-ZZ-human IgG were added into wells that contain ErbB2 over-expressing SKBR3 cell line (black bars) or human mammary carcinoma MDA-MB231 cells as control cell line (gray bars) that express a low level of ErbB2. Binding was evaluated by the addition of HRP-conjugated rabbit anti M13 antibodies followed by addition chromogenic HRP substrate TMB. The results were plotted as absorbance at 450 nm. Data represent mean values ± SD of quadruplicate phage samples taking from one of three independent experiments.