Our staff scientists have extensive experience in screening of phage display peptide, cDNA and scFv/Fab libraries. In particular, by conducting library screening and panning for four cycles, we normally get scFv/Fab antibodies of an affinity( of 10-7). By constructing serial sub-libraries of the isolated scFv/Fab antibodies, allows increase of the affinity of the scFv antibodies . We have successfully obtained a scFv antibody that has an extremely high affinity of 10-12, whose binding to the antigen is essentially irreversible