Stability analysis and intracellular uptake of rGel fusion toxins. A. Extent of degradation following exposure of 1 μM to 2008 cells for 6 h. The medium and cells were subjected to Western blot analysis with anti-rGel antibody. B. Internalization of rGel, CPE-G4S-rGel and R9-rGel into 2008 cells. Cells were treated with 250 nM of each fusion toxin for 6 h and stained with rabbit anti-gelonin antibody and Texas red-coupled anti-rabbit secondary antibody. Nuclei were stained with Hoechst 33342 (blue).