Binding specificity of selected phage from the Ph.D.-12 library. Wells of 96-well microtitre plates were coated with mAb U001 and BSA (10 μg/ml, 100 μl) by incubation at 4°C overnight and blocked with 5% BSA in TBS. Affinity-selected phage were added to the wells and allowed to bind at 37°C for 1 h. After the unbounded phage was removed, the bound phage was detected by incubation with peroxidase-labelled murine anti-M13 antibodies. The bound peroxidase was determined by incubation with O-phenylenediamine dihydrochloride and the reaction was determined in an ELISA reader at OD492. All the assays were carried out in triplicate and the error bars indicate standard deviation.