Toluidine Blue O

Property Data Common name Suggested name Other names C.I. number C.I. name Class Ionisation Solubility aqueous Solubility ethanol Absorption maximum       Colour Empirical formula Formula weight Toluidine blue Toluidine blue O Tolonium chloride 52040 Basic blue 17 Thiazin Basic 3.82% 0.57% 620-622 (Conn) 632 (Gurr) 640.4 (Merck) 626 (Aldrich) Blue C15H16N3SCl 305.8

Toluidine blue O is a metachromatic dye, and is frequently employed in that capacity. It is a blue nuclear counterstain, and can be used to demonstrate Nissl substance. It is useful for staining mast cell granules, both in metachromatic and orthochromatic techniques. Compare its formula to other methylene blue homologues.

 

Reference
R. D. Lillie.
Conn's Biological Stains
Williams & Wilkins, Baltimore, MD., U.S.A.

Aldrich chemical catalogue, 1992
Aldrich Chemical Company, Milwaukee, WI, USA.

Edward Gurr, (1971)
Synthetic dyes in biology, medicine and chemistry
Academic Press, London, England.

Susan Budavari, Editor, (1996)
The Merck Index, Ed. 12
Merck & Co., Inc., Whitehouse Station, NJ, USA