Ninty-six-well ELISA plates (Falcon, CA, USA) were seeded with either cancer or control cells. Individual phage particles were added to the cell-coated plates and incubated, followed by incubation with horseradish peroxidase (HRP)-conjugated mouse anti-M13 monoclonal antibody (mAb) (Pharmacia, Uppsala, Sweden) and subsequently with the peroxidase substrate ophenylenediamine dihydrochloride (Sigma, MO, USA). The reaction was stopped and absorbance was measured at 490 nm using an ELISA reader. The selected phage clones were further analyzed using DNA sequencing. The sequencing was performed with the primer 59-CCCTCATAGTTAGCGTAACG-39 corresponding to the pIII gene sequence. The phage-displayed peptide sequences were translated and aligned using GCG program.