 Here, the method is used to view viruses, bacteria, bacterial flagella, biological membrane structures and proteins or protein aggregates, which all have a low electron-scattering power.Some stains, such as osmium tetroxide and osmium ferricyanide, are very chemically active.As strong oxidants, they cross-link lipids mainly by reacting with unsaturated carbon-carbon bonds, and thereby both fix biological membranes in place in tissue samples and simultaneously stain them.