Fig. 1. Localization of Rab27 on WPBs in HUVECs by immunofluorescence microscopy. HUVECs grown on gelatine-coated glass coverslips were fixed, permeabilized and double immunolabelled for VWF (A,D and red in C,F) and endogenous Rab27 (B,E and green in C,F). Arrows in C and F point to WPBs that are positive for both VWF and Rab27, and the curly brackets indicate the population of VWF-positive organelles that do not stain for Rab27. Scale bar, 20 µm (F).