In the case of silver stained protein bands the destaining is accomplished by oxidation of the metallic silver attached to the protein by potassium ferricyanide or hydrogen peroxide ( H 2 O 2 ).
22.
It is common practice to perform this reaction using a catalytic amount of osmium tetroxide, which after reaction is regenerated with either potassium ferricyanide or " N "-methylmorpholine " N "-oxide.
23.
Potassium ferricyanide is also one of two compounds present in ferroxyl indicator solution ( along with phenolphthalein ) which turns blue ( Prussian blue ) in the presence of Fe 2 + ions, and which can therefore be used to detect metal oxidation that will lead to rust.
24.
Potassium ferrocyanide is used in a mixture with potassium ferricyanide and phosphate buffered solution to provide a buffer for beta-galactosidase, which is used to cleave X-Gal, giving a bright blue visualization where an antibody ( or other molecule ), conjugated to Beta-gal, has bonded to its target . On reacting with Fe ( 3 ) it gives a Prussian blue colour.
