Mapping of the scFv 43M2 and 51 epitopes on E7 protein by immunoassays. Western Blotting and ELISA were performed using as antigens two 16E7 deletion mutants respectively representing NH2-term and COOH-term of the 16E7 protein. Panel A: schematic representation, with functional domains, of full-length 16E7 and 16E7 deletion mutants produced as GST-fusion proteins and used for the mapping of the scFvs. Panel B: Western blotting. Each antigen-containing strip was incubated with the purified scFvs 43M2 (M2), 51 and a mouse anti-Flag mAb. The control stripes were incubated with commercial anti-16E7 (M) and anti-GST monoclonal antibodies (mAb) in mouse, an in-house anti-16E7 polyclonal antibody (P) or no antibody (CTR). An anti-mouse peroxidase-conjugated mAb was used as a secondary antibody in all cases. The immunocomplexes were visualised by chemioluminescence. Panel C: ELISA. The coating was performed with the same proteins utilised for WB, and the incubation performed with the same primary and secondary antibodies, as indicated. The immune-complexes were revealed following incubation with the peroxidase substrate by reading the OD at 450 nm (OD450). The dashed lines represent the cut-off values for each experiment, corresponding to the OD450 values obtained using the anti-GST mAb.