Figure 3.

Analysis of binding specificity of Z_{HPV16 E7} affitoxin384 to HPV16 E7 by indirect immunofluorescence assay. SiHa and CaSki cells (HPV16-positive) incubated with Z_{HPV16 E7} affitoxin384 were used as the tested cells. HeLa and A375 cells (HPV16-negative) with the same incubation were used as control cells. (A) Cells without incubation with affitoxin were analyzed with anti-HPV16 E7 rabbit serum antibody as positive controls. (B-D) Cells incubated with Z_{HPV16 E7} affitoxin384 were analyzed with three different kinds of primary antibodies against His tag, PE38KDEL and SPA-Z, respectively. (E) Cells incubated with Z_{HPV16 E7} 384 were analyzed with the primary antibody against His tag as positive control. (F) Cells incubated with Z_wt affitoxin were analyzed with the primary antibody against SPA-Z as negative control. All corresponding secondary antibodies were labelled with FITC (green). The nuclei of cells were stained with PI (red). Fluorescence signals were observed using a confocal fluorescence microscope. Scale bar = 10 μm.