Fig. 7. Stimulation-dependent uptake of endocytotic tracer dye. (A-C) Uptake of Alexa563-hydrazine (red; B) in cells expressing IAPP-emerald (green; A). Vesicles containing only Alexa563-hydrazine are highlighted by white circles, and vesicles containing both labels are highlighted by yellow circles and appear yellow when the images are merged, as shown in C. Exocytosis was stimulated for 30 seconds with 87 mM KCl, followed by washing on ice. (D-F) As in A-C, but the cells were incubated in standard EC solution (5 mM KCl) containing Alexa563-hydrazine.