TEM analysis. TEM analysis of both the recombinant rVWFWT (A) and heterozygous in cis rVWFWT/rVWF924Q-2178S form (B) and images obtained with AFM of the recombinant WT (C) and mutant (D) VWF form. (A-B) The sample could adsorb on the carbon film for 5 minutes, and the sample excess was removed with filter paper. After staining with a 2% uranyl acetate solution for 30 seconds in the dark at room temperature, staining excess was also removed with filter paper and the grid washed with ultrapure water. Grids were then air-dried for 1 hour before observation at room temperature. TEM micrographs were collected, working with an acceleration voltage of 120 keV at a magnification of ×30 000 (Libra 120; Carl Zeiss Meditec, Jena, Germany). Notably, a great difference in the conformational state between the 2 forms can be observed. Even in the absence of shear stress, the conformation is globular for the WT VWF, whereas it is mainly unfolded for the mutant, which forms strains interacting each other. The samples were dry in the TEM method (tungsten-coated, brightfield-imaged), whereas they were (C-D) fully hydrated in the AFM experiment.