2.7 Electron microscopy observation
Took 20 µl of virus suspension with a pipet-gun and dropped onto the copper grid with carbon film for 3-5min, and then use filter paper to absorb the excess liquid. Dropped 2% phosphotungstic acid on the copper grid to stain for 1-2min, use filter paper to absorb excess liquid, and dry at room temperature. The cuprum grids are observed under TEM and take images.