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Hughesdon’s Metachromatic Stain

Hughesdon's Metachromatic Stain



Staining solution

Azure A0.2g
Distilled water100mL

Differentiating solution

Uranyl nitrate0.2g
Distilled water100mL

Tissue Sample

Paraffin sections of neutral buffered formalin fixed tissue are suitable. Mercuric chloride fixatives are reputed to emphasise metachromasia. Other fixatives may be satisfactory.


  1. Bring sections to water via xylene and ethanol.
  2. Do a Mallory bleach using 1% potassium permangate alone for 5 minutes.
  3. Place in to staining solution for 5 minutes.
  4. Rinse with tap water.
  5. Place into the differentiating solution for 10 seconds.
  6. Rinse with tap water.
  7. Blot dry, dehydrate with absolute ethanol.
  8. Clear with xylene and mount with a synthetic resinous medium.

Expected Results

  • Acid mucopolysaccharides – Red/purple
  • Mast cells – Red/purple
  • Background – Blue


  • The time of differentiation should be adjusted to give good color contrast.
  • Metachromatically stained materials include acid mucins, cartilage, connective tissue ground substance, and mast cell granules.
  • It may be difficult to obtain uranyl nitrate due to restrictions placed on its distribution in some jurisdictions.

Safety Note

Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.


  1. Drury, R A, and Wallington, E A, (1967).
    Carleton’s histological technique., Ed. 5. pp. 2250
    Oxford University Press, London, England.