Internalization and intracellular targeting of TAT-SA combined with biotin in HeLa cells. (A) Cells were transduced with the complex of TAT-SA-A488 (green) and biotin-DY-633 (purple), followed by TRITC-labeled dextran (10 kD, red) prior to live cell imaging at 4 h post transduction (B). Cells were transfected with TAT-SA complexed with biotinylated PPAA and biotin-DY-633. Cells were fixed with PFA, permeabilized with Triton-X and immunolabeled with rabbit anti-SA Ab followed by Alexa-488-conjugated goat anti-rabbit IgG (green) and embedded with DAPI-containing Mowiol-Dabco (nucleus, blue). All images are 3D projections of the nuclear area. Scale bars 10 μm.