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Water Blue

Water Blue

Ionisation: Acid

Chemical structure of Water Blue

Common Name: Water blue
Suggested Name: Water blue
Other Names:

Aniline blue

C.I. Number: 42755
C.I. Name: Acid blue 22
Color: Blue
Solubility Aqueous: Highly
Solubility Ethanol: Highly
Absorption Maximum: 595-610 (Conn) 582 (Gurr)
Empirical Formula: C32H25N3O9S3Na2
Formula Weight: 737.8


Water blue and methyl blue are the constituents of aniline blue WS, a dye which traditionally has been a variable mixture of the two, although Gurr uses the name aniline blue instead of water blue for it. Any of the three will generally be found suitable for staining collagen in Masson's trichrome and Mallory's method for connective tissue.


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