GALLYAS stain (stock solution II) is an aqueous solution containing ammonium nitrate, silver nitrate and tungstate silica hydrate. It is used in combination with stock solution I and other components in GALLYAS staining, which is applied in histological examination.

In application, GALLYAS staining is mainly known for imaging neurofibrillary tangles, degenerative changes in nervous tissue and Alzheimer's disease-associated structures. The chemical mode of operation of stock solution II lies in the reduction of silver ions to elemental silver by the tungramato-silica hydrate. The ammonium nitrate acts as a catalyst, while the silver nitrate serves as a silver source.

The particular suitability of this stock solution lies in its role in producing a selective and high-contrast staining image of the relevant structures in histological specimens. Stock solution II has been specially developed for the examination of nervous tissue and for the identification of neurodegenerative changes. The application of this stock solution is aimed at specific problems in histology and is not intended for general staining. Together with Stock Solution I and other components of GALLYAS staining, it enables precise analysis of the tissue samples examined.