All Photos(3)



Toluidine Blue O

Technical grade

Tolonium chloride, Methylene Blue T50 or T extra, Basic Blue 17, Blutene chloride
Empirical Formula (Hill Notation):
CAS Number:
Molecular Weight:
Colour Index Number:
EC Number:
MDL number:
PubChem Substance ID:

Quality Level




Dye content, ~80%


H2O: 1 mg/mL


diagnostic assay manufacturing

storage temp.

room temp

SMILES string




InChI key


Looking for similar products? Visit Product Comparison Guide

General description

Toluidine Blue O (TBO) is a thiazine dye of the quinone-imine family and is cationic in nature. It has been employed in polychromatic staining of paraffin embedded plant cell walls. It is a metachromatic dye suitable for a wide variety of histological staining procedures.
A metachromatic dye suitable for a wide variety of histological staining procedures.


Toluidine Blue O has been used to stain a variety of specimens like mesenchymal cells, taste buds, osteoblasts, matrix, etc.


5, 25, 100 g in glass bottle

Storage Class Code

13 - Non Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves

Certificate of Analysis

Certificate of Origin

  1. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  2. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  3. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  4. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  5. Is there a difference between Toluidine Blue O and Toluidine Blue and which is best for staining tissue sections?

    Toluidine Blue O and Toluidine Blue are generally regarded as synonyms. The dye can be found in 2 forms. There is a chloride form and zinc chloride double salt.  Products T3260 and 198161 are the chloride form. This is the form certified by the Biological Stain Commission. The dye listed as simply Toluidine Blue, Product 89640, is the zinc chloride double salt. For routine use today, the chloride form should be utilized. The product number recommended for biological/histological staining is Product 198161, Toluidine Blue O.  This product has been found to provide acceptable staining of tissue by the Biological Stain Commission. Products 198161 and 89640 have not been suitability tested for the staining of tissue sections.

  6. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

Mrinalini Sharma et al.
Antimicrobial agents and chemotherapy, 52(1), 299-305 (2007-10-31)
Staphylococci are important causes of nosocomial and medical-device-related infections. Their virulence is attributed to the elaboration of biofilms that protect the organisms from immune system clearance and to increased resistance to phagocytosis and antibiotics. Photodynamic treatment (PDT) has been proposed
Polychromatic staining of plant cell walls by toluidine blue O
Protoplasma, 59(2) (1964)
The canine epiphyseal-derived mesenchymal stem cells are comparable to bone
marrow derived-mesenchymal stem cells
Surgery (2015)
Kyungho Yoon et al.
Ultrasound in medicine & biology, 45(9), 2391-2404 (2019-06-21)
Transcranial application of focused ultrasound (FUS) combined with vascular introduction of microbubble contrast agents (MBs) has emerged as a non-invasive technique that can temporarily create a localized opening in the blood-brain barrier (BBB). Under image-guidance, we administered FUS to sheep
Arecoline Alters Taste Bud Cell Morphology, Reduces Body Weight, and Induces Behavioral Preference Changes in Gustatory Discrimination in C57BL/6 Mice
Wei-Hau Peng
Chemical Senses (2016)

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service