Fig. 7.

Binding of the selected DARPins to NTR1 expressed in mammalian cells detected using fluorescence microscopy. COS-7 cells were transfected with (A) pcDNA3.1-Flag-KOR-MBP-Myc-His₆, or (B and C) pcDNA3.1-D03-Myc-His₆, as described in Materials and methods. In (B) and (C), two different DARPins were tested, in (B) the negative control DARPin P14 and in (C) the specific DARPin P28. (A1–C1) Staining of the cell nuclei with DAPI, (A2–C2) staining of the receptors using mouse anti-Myc and goat anti-mouse-AlexaFluor-555-labeled antibodies, (A3–C3) detection of the receptors using the DARPin-sfGFP fusions indicated and (A4–C4) merged pictures from the blue, red and green channels.