Gallocyanin stain

It has been known since the early work of Einarson (1932) that the gallocyanin dye worked well for nucleotide constituents.^[2] Gersch and colleagues at Chicago are often credited with the earliest efforts of using gallocyanin for staining.

Sandritter demonstrated that a stoichiometric relationship occurs between intensity of staining and quantity of nucleic acid present.^[3]

Its method of binding and specificity are still not completely known. However, it is thought that gallocyanin-Cr(H₂O)₄ selectively binds to nucleic acid phosphate groups, particularly within a pH range of 1.5-1.75.^[2]