Factor VIII-YFP induces morphologic transition from elongated cigar-shaped structures to round circular-shaped organelles. (A) HEK293 cells were cotransfected with VWF-CFP and P-selectin. Cells were stained for P-selectin using rabbit polyclonal anti–human CD62P antibody. Shown is double-fluorescent detection of representative 3-dimensional projections (Z-stacks 0.4 μm). VWF-CFP, P-selectin, and regions of colocalization are shown in red, green, and yellow, respectively. The scale bar represents 10 μm. (B) HEK293 cells stably expressing FVIII-YFP were transfected with VWF-CFP. Shown is double-fluorescent detection of representative 3D projections (Z-stacks 0.4 μm). VWF-CFP, FVIII-YFP, and regions of colocalization are shown in red, green, and yellow, respectively. The scale bar represents 10 μm. (C) HUVECs were nucleofected with FVIII-YFP (left panel) or VWF-YFP (right panel). Endogenous VWF was stained using monoclonal antibody CLB-Rag35. Shown is the merge of double-fluorescent detection. Endogenous VWF is shown in red, FVIII-YFP (left panel) and VWF-YFP (right panel) are depicted in green, and regions of colocalization are yellow. The inset shows the morphology of vesicles. The scale bar represents 20 μm.