The optimal thickness of gold coating of cilia for scanning electron microscopy was studied using respiratory mucosa obtained from pigs. We tested 8 different coating times, from 10 seconds to 4 minutes, which resulted in gold layer thicknesses varying from 16 ± 1 nm to 100 ± 3 nm. The thickness of the gold layer with a coating time of 60 seconds and voltage of 2.5 kV was 43 ± 5 nm. This thickness of gold layer gave good image quality without causing any electric charging. With thinner gold films, the amount of electric charging increased. When the coating time was longer, the gold layer was thicker but image quality did not improve. The thicknesses of the gold layers were measured using transmission electron microscopy (TEM).
Toskala, E.; Nuutinen, J.; Rautiainen, M.; and Pelttari, A.
"Gold Coating of Respiratory Cilia for Scanning Electron Microscopy,"
Scanning Microscopy: Vol. 9
, Article 23.
Available at: https://digitalcommons.usu.edu/microscopy/vol9/iss1/23