Fig. 7. WPBs manoeuvre within cells by folding at hinges. (A) HUVECs were fixed, permeabilised and labelled for VWF by indirect immunofluorescence (see Materials and Methods). The gallery shows a selection of the possible shapes of WPB, as seen by confocal microscopy. Bar, 2 µm. (B) HUVECs were transfected with VWF-GFP. A time-lapse movie (see Materials and Methods) was made 2 days after transfection. The sequence shows the movement of a single WPB over a 24-minute time period. Bar, 4 µm. See also Movie 1. (C,D) Images of WPBs after HPF and freeze substitution confirm that WPBs can bend as well as twist and branch. Bars, 200 nm (C) and 500 nm (D).