2.

Localization of D-R8 in cells. HeLa (A) and A549 (B) cells were incubated for 1 hr at 37°C with 2 μM of the D-enantiomerof R8-Alexa488 peptide (RRRRRRRRGC-Alexa488) and immediately analysed by scanning confocal fluorescence microscopy combined with scanning Direct Interference Contrast. Shown are superimposed images from 25 to 30 sections through the Z-axis. The peptide-labelled vesicles in these cells are concentrated in a perinuclear region but it remains to be seen whether any are, or are derived from, macropinosomes. Previous studies in HeLa cells show a significant fraction of these to be late endosomes and lysosmes [110]. Scale bar 15 μM.