Cresyl Violet Stains Mast Cells Selectively: Its Application to Counterstaining in Immunohistochemistry

Abstract

The thiazine dye toluidine blue (TB) is well known to stain mast cells and hyaline cartilage metachromatically, and thus is mostly often used for their identification. However, TB is not suitable for counterstaining in immunohistochemistry, because of its high-background staining in the cytoplasm of other cell species and in extracellular structures. To expand the knowledge about dyestuffs staining mast cells in consideration with their usage in immunohistochemistry, we determined the stainability of several thiazines and oxazines, which are structurally related compounds to TB, using sections of mast cell-containing tissues. We found that all azine dyes used metachromatically stained mast cells and cartilage. Among these dyes, an oxazines cresyl violet (CV) stained mast cells with lower background, suggesting that those are useful for detecting mast cells and for counterstaining in immunohistochemistry. To ascertain its utility, CV was used in immunostaining of bHSDs in sections from adult rat ovary. Immunopositive signals reflected by DAB development in brown were clearly detected even after CV staining. We conclude that, similar to thiazines, oxazines stain mast cells metachromatically, and that of these, CV is more useful as a counterstain in immunohistochemistry than TB.

Modern Imaging Technologies of Mast Cells for Biology and Medicine (Review)

“…More rarely, for metachromatic staining of mastocytes, other dyes are used: cresyl violet [73] or thionin. Thionin ranks below in mast cell detection efficiency compared to toluidine blue and gives more background REVIEWS staining [72, 74,75].…”

Modified bismarck brown staining for demonstration of soft tissue mast cells

“…Probably the most commonly employed one is the Toluidine blue staining, which shows the mastocytic granules as metachromatic structures (8), however producing a good amount of background staining of other cellular and extracellular elements (9). Such high signal-to-noise ratio can make evaluation of the resulting histological preparation ambiguous.…”