NanoVan® (methylamine vanadate) is based on vanadium, which has a lower atomic number (23) than other elements commonly used as negative stain reagents such as uranium (92) or tungsten (74). NanoVan® is recommended for samples labeled with Nanogold®, since it does not obscure visibility of the small 1.4 nm gold as do the higher atomic number stains. It may also be used in other standard negative stain work since it has excellent staining properties (see: Tracz, E., et. al.: Brain Res., 773, 33-44 (1997)).
Features of NanoVan®
Produces a light, very uniform negative stain for high-resolution fine structure visualization.
Stable, non-volatile in the electron beam, more resistant than uranyl acetate.
Does not denature protein samples.
Excellent spreading properties.
Near-neutral pH of 8.
Supplied ready-to-use as a 2 % solution in water.
Permits visualization of Nanogold®.
Nano-W® (Methylamine Tungstate)
Nano-W® (methylamine tungstate) is a negative stain based on an organotungsten compound. It has excellent spreading qualities and a high density for high contrast. It may be mixed with the lower atomic number NanoVan® to produce intermediate stain densities. It has a pH of 6.8.
For some images of negatively stained virus particles and more information on the technique in general, see Linda Stannard's Virus ultrastructure pages (University of Cape Town).