SIM imaging of pseudo-WPB formation in recombinant homozygous in-frame deletions. Expression of WT rVWF produced numerous pseudo-WPB (A), which, on close inspection, had bright outer membrane staining (B). (C) rVWF3del expression produced a diffuse, speckled network-like staining pattern. (D) No large VWF-positive structures were visible. (E) rVWF32-34del expression also produced a more diffuse staining pattern, although with apparent VWF-positive structures. (F) However, the VWF-positive structures displayed uniform staining intensity and nonuniform structure, possibly representing aggregates of VWF oligomers. rVWF33-34del expression was able to form pseudo-WPB like structures (G); however, numerous rounded structures were also visible (H). Scale bars, 5 μm (A,C,E,G) and 1 μm (B,D,F,H). Panels B, D, F, and H are higher magnifications of the region of interest in panels A, C, E, and G (denoted by the white box).