Fig. 2

Premarking process improves the distribution of nano-gold particles on the grid. (A) Representative SXT images of R2/2 200-mesh grid without (control, left) and with (premarking, right) pre-incubation of 100 nm nano-gold particles. Arrow indicates nano-gold particle. Scale bar: 5 μm. (B) Illustrated workflow of premarking process. Glow discharged grids were submerged in the nano-gold solution dropped onto a parafilm-covered glass slide. After 1-hour incubation, grids were transferred onto filter paper. An additional nano-gold solution was added to the grids. Next, the premarked gold grids were dried overnight in a 5% relative humidity (RH) dryer for further experiments