Fig. 3.

Screening of clones selected against overexpressed targets. A, Screening of clones selected against biopsy lysates. For each selection, 96 clones were randomly picked and assayed by phage ELISA for binding to biopsy or healthy cell lysates immobilized on microtiter plates. Clones positive on biopsy lysates and negative on normal lysates were considered cancer specific. Dep.: depletion. Dep. + masked sel.: depletion followed by selection performed in the presence of masking sdAbs. B, Screening of sdAbs isolated against intact breast cancer cells. For each selection, 96 clones were screened by phage-cytometry assay on a mixture of intact breast cancer cells (MDA-MB-231, MCF7, SKBr3, HCC1954). Bound phage-sdAb were detected using PE-conjugated anti-M13 mAb. Dep.: depletion. Dep. + masked sel.: depletion followed by selection performed in the presence of masking sdAbs.