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Methylene Green

Methylene Green

Class: Thiazin
Ionisation: Basic

Chemical structure of Methylene Green
Chemical structure of Methylene Green

Common Name: Methylene green
Suggested Name: Methylene green
Other Names:

C.I. Number: 52020
C.I. Name: Basic green 5
Color: Green
Solubility Aqueous: 3% (Aldrich) 1.46% (Conn)
Solubility Ethanol: 3% (Aldrich) 1.46% (Conn)
Absorption Maximum: 657, 618 (Aldrich) 660, 607 (Conn)
Empirical Formula: C16H17N4O2SCl
Formula Weight: 433 (Aldrich) 364.9 (Conn)


Methylene green is not commonly used in medical histotechnology. It stains nuclei green, and is sometimes used as a counterstain to red or purple primary stains.

The formula on the left is from Aldrich, that on the right from Conn.


  1. R. D. Lillie.
    Conn’s Biological Stains
    Williams & Wilkins, Baltimore, MD., U.S.A.
  2. Aldrich chemical catalogue, 1992
    Aldrich Chemical Company, Milwaukee, WI, USA.