Fig. 4

Selectivity analysis of phage clone bearing MHIVPHE peptide in cross-reactivity ELISA assay. a Schematic representation of M13—phage clone bearing Cu (II) peptide. b Cross-reactivity assay of M13-Cu (II)-peptide. The microtiter plate was functionalized and modified with Cu (II), Mn (II), Hg (II), Ni (II), Pb(II) ions, and 100 µL of 10⁹ PFU selected clones were incubated per well. The plate was washed ten times, and nonbounded phages were discarded. 100 µL of 0.2 M Glycine–HCl (pH 2.2) was used for phage elution. Eluted phages were titrated in accordance with the procedure outlined in the manual for The Ph.D.™-7 Phage Display Peptide Library Kit. As the phage titer is eluted from wells coated with different metal ions, binding cross-reactivity and specificity is demonstrated. The mean of three independent experiments is presented; PFU plaque-forming unit