4.2.4 Transmission electron microscopy of ANVs and THB@ANVs
The ANVs and THB@ANVs samples were initially fixed by equal volume of 4% paraformaldehyde in PBS for 1 h, then applied to carbon Formvar film-coated transmission electron microscopy (TEM) grid, and incubated for 20 min at room temperature. After washing with PBS, the samples were fixed with 1% glutaraldehyde for 5 min, and stained with 1% uranyl acetate for 30 s, then dried before viewing.