Methylene blue

certified by the Biological Stain Commission

Basic Blue 9, Tetramethylthionine chloride, 3,7-bis(Dimethylamino)phenazathionium chloride
Empirical Formula (Hill Notation):
C16H18ClN3S · xH2O
CAS Number:
Molecular Weight:
319.85 (anhydrous basis)
Colour Index Number:
Beilstein/REAXYS Number:
EC Number:
MDL number:
PubChem Substance ID:


certified by the Biological Stain Commission

Quality Level




Dye content, ≥82%


hematology: suitable
histology: suitable


H2O: 4mg/4ml

Featured Industry

Diagnostic Assay Manufacturing

storage temp.

room temp

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InChI key


Gene Information

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General description

Methylene blue is a compound that occurs as crystals or crystalline powder, having a bronze-like luster. It is soluble in water, chloroform and partially soluble in alcohol. It is a photoactive dye, which is a member of phenothiazine family.


Methylene blue has been used:
  • to stain vaginal cells
  • for the preparation of protein aqueous ink
  • to evaluate cell survival by staining


25, 100 g in glass bottle

Biochem/physiol Actions

Methylene blue is used as a bacteriologic stain or dye and indicator. It mediates the inactivation of enveloped viruses in plasma, when exposed to visible light. It is an inhibitor of nitric oxide synthase and guanylate cyclase. It also plays a key role in medicine as an antimalarial agent, reducing agent in methemoglobinemia and inducer of apoptosis in cancer cells.


Certified for use in Mallory′s phloxine-methylene blue stain; Levine & Black stain for bacteria in milk; Wright stain for blood smears.


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Signal Word


Hazard Statements

Precautionary Statements

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves


NONH for all modes of transport

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

Certificate of Origin

  1. What is the solubility of Methylene blue, Product M9140?

    The product is soluble in water at 50 mg/mL, EGME at 60 mg/mL and ethanol at 70 mg/mL. EGME is an abbreviation for ethylene glycol monomethyl ether, also known as 2-methoxyethanol or methyl cellosolve.

  2. How can Methylene blue, Product M9140, be used?

    Probably its most important application is as an in vitro diagnostic bacteriology, cytology, hematology, and histology stain. Methylene Blue serves as a precursor to the Methylene Azures and as a component of the various Ramanowsky-type blood stains (Wright, Leishman, Giemsa and others). While pure Methylene Blue is not a good nuclear stain, it readily undergoes oxidative demethylation to form the various Methylene Azures, which are good nuclear stains.

  3. How is dye content determined for Methylene blue, Product M9140?

    Dye content is determined spectrophotometrically by noting the dye's absorbance peak, which is typically near 665 nm, or by calculating the ratio of the absorbances at 650 nm over 680 nm. (The dye exhibits smaller peaks at approximately 292 and 246 nm).

  4. 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.

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Hawley's Condensed Chemical Dictionary (2016)
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