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Nile Blue A

Nile Blue A

Class: Oxazin
Ionisation: Basic

Chemical structure of Nile Blue A

Common Name: Nile blue
Suggested Name: Nile blue A
Other Names:

Nile blue sulphate

C.I. Number: 51180
C.I. Name: Basic blue 12
Color: Blue
Solubility Aqueous: Soluble
Solubility Ethanol: Soluble
Absorption Maximum: 635-645 (Conn) 637 (Gurr) 633 & 638 (Aldrich)
Empirical Formula: C20H20N3OCl
Formula Weight: 353.9

Description

Nile blue A forms a red staining lysochrome, named nile red, when it is boiled with dilute sulphuric acid. During this treatment, oxygen is substituted for an amino group converting it to the other dye. It is from this ability that nile blue A gains its value in histology. The red lysochrome remains dissolved in aqueous mixture with Nile blue A, but will preferentially stain lipids from the solution, colouring them red. The Nile blue, in turn, stains the nuclei and background blue in contrast.

References

  1. R. D. Lillie.
    Conn’s Biological Stains
    Williams & Wilkins, Baltimore, MD., U.S.A.
  2. Edward Gurr, 1971
    Synthetic dyes in biology, medicine and chemistry
    Academic Press, London, England.
  3. Aldrich chemical catalogue, 1992
    Aldrich Chemical Company, Milwaukee, WI, USA.