Sherman M B, Orlova E V, Terzyan S S, Kleine R, Kiselev N A
Ultramicroscopy. 1981;7(2):131-8. doi: 10.1016/0304-3991(81)90002-4.
It has been shown that in some cases negative staining reveals structure with details down to 0.4 nm in size, the nature of protein playing a key role. Various stains seem to interact with different parts of a thermitase (a serine protease) molecule, which results in intensity changes in electron diffraction patterns.