Five microliters of miR-44438–NCMB was applied to a copper grid with a carbon support membrane. After a 60-s incubation, the excess sample was removed with filter paper and stained with a 2% uranyl acetate solution for 60 s. The excess uranyl acetate solution was removed with filter paper and by air-drying. Electron microscope images were collected using a Tecnai F20 TEM at 200 kV.