Map of phagemid vector, pMod1, for the construction of scFv phage-display library. This 4541-base-pair (bp) vector was modified from pHage 3.2 (Maxim Biotech, Inc.), which was derived from M13. Transcription is under control of the lac promoter. The ampicillin resistant gene is for the selection and maintenance of the phagemid. The phagemid carries Fi and ColEi origin of replication for amplification in phage and E. coli. The secretion of the scFv fragment is directed by gene III signal peptide. The scFv genes are cloned between SfiI and NotI for display on the phage coat protein, pIII. An amber stop codon in frame with and immediately following hexahistidine-tag and Myc-tag permit the expression of scFv as a fusion with gene III in an amber suppressor host (TG1) or as a fusion with only the 6 × His-tag and Myc-tag in a non-suppressor host strain (HB2151). The scFv fragment is fused with hexahistidine tag and Myc tag for affinity purification and immuno-detection, respectively. The coding region of a gene III leader peptide and the multiple cloning sites is shown with the position of 6 × His, Myc tags and amber stop codon. The map was not drawn to scale. The sequences around the cloning sites were shown at the bottom of the figure.