Transmission Electron Microscopy (TEM)
REF proteins after incubation in PBS were absorbed 10 min onto Formvar-coated, carbon-stabilized copper grids (400 mesh) and washed 3 times with water. Grids were then negatively stained 1 min with 10 µL of freshly prepared 2% uranyl acetate in water, dried with filter paper, and examined with a Hitachi H7650 transmission electron microscope (Hitachi, Krefeld, Germany) at an accelerating voltage of 80 kV. TEM was performed at the Pôle Imagerie Electronique of the Bordeaux Imaging Center.