Magnetron sputtering deposition of ultra-thin metal coatings for the visualization of protein-containing objects of nanometer size by electron microscopy

Abstract

Electron microscopy is widely used in biological and medical research, enabling to obtain images of the investigated objects with nanometer resolution. Exposure of biological objects under electron beam during the visualization can, however, cause their damage. Destructive effect of the electron beam can be significantly decreased by formation of metal coating on the surface of the objects to be studied. In the present study, an approach for the formation of ultra-thin metal coatings on the surface of protein-containing structures is proposed. Magnetron sputtering in argon plasma in DC mode was employed to form 8 Å-thick tungsten films on the surface of model protein-containing objects— tobacco mosaic virus particles — for their subsequent visualization by electron microscopy.