Negative Staining

5µl of the sample is adsorbed for 1 minute to a carbon coated grid that has been made hydrophilic by a 20 second exposure to a glow discharge (25mA). Excess liquid is removed with a filterpaper (Whatman #1), the grid is then floated briefly on a drop of water (to wash away phosphate or salt), blotted again on a filer paper and stained on a drop of 0.75% uranyl formate (EMS catalog # 22451) or 1% Uranyl Acetate (EMS catalog # 22400) for 20-30 seconds. After removing the excess stain with a filter paper the grids can be examined in a Transmission electron microscope.