Figure 1. Identification of an endometriosis-targeting peptide by subtractive phage library screening.

(a) Illustration of library screening steps. A peptide displaying phage library was selected by subtraction using female mouse peritoneum followed by adhesion to and internalization by Ishikawa cells. (b) Binding efficiency of phage pools obtained after each screening round assessed by plaque-forming assay. (c) Binding of cloned phage to Ishikawa (purple bars) and control A431 (red bars) cells. (d) Z13 phage binding to endometrial cell lines (blue bars) and control non-endometrial cell lines (pink bars). In c,d, each cloned phage was added to a monolayer of each cell line at 37 °C for 30 min. Internalized phage was counted by a plaque-forming assay. Experiments shown in panels b–d were repeated three times. Each error bar represents s.d.