Fig. 7.

a Fluorescence signal of Sicastar Red (30 nm in size, 6 μg/ml) exposed to H441 (uc untransfected, neg non-targeted siRNA, F12 siRNA against flotillin-1/2) in conventional monoculture for 4 h in serum-free medium with further 20-h cultivation in fresh serum-containing medium. Furthermore, transfected H441 were stained via immunofluorescence for flotillin-1 (b) and flotillin-2 (c). Pictures were taken by means of a fluorescence microscope (DeltaVision, Applied Precision). For appropriate comparison, exposure time and intensity scale was equally adjusted. Flotillin-1/2-depleted cells take-up less Sicastar Red than non-targeted siRNA and untransfected cells. Nuclei are stained using Hoechst 33342 (blue), scale bar 5 μm