Fig. 3. Tubule organisation in immature WPBs. After HPF, immature WPBs found in the juxta-Golgi region of HUVECs were examined to assess their organisation. (A) A clathrin-coated immature WPB containing a single tubule of VWF. Bar, 200 nm. (B) A WPB containing two tubules that are disordered. The tubules touch the membrane only at the tip of the WPB. Bar, 200 nm. (C,D) More elongated WPBs containing three and seven tubules, respectively, which, while disorganised, together extend over the full length of the WPB. Bars, 500 nm (C) and 200 nm (D). (E) WPBs were grouped using the number of tubules apparent in the section and the width was measured. n=4-20 per bar; error bars represent standard error.