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Eosin for Eosinophils



for Eosinophils



Tissue Sample

5µ paraffin sections of neutral buffered formalin fixed tissue are suitable. Other fixatives are likely to be satisfactory.


  1. Bring sections to water via xylene and ethanol.
  2. Stain nuclei lightly with alum hematoxylin.
  3. Differentiate if necessary and blue.
  4. Place in eosin solution for 5 minutes.
  5. Wash well with tap water until sections are almost unstained.
  6. Dehydrate with ethanol, clear with xylene and mount with a resinous medium.

Expected Results

  • Nuclei – blue
  • Eosinophils – bright pink
  • Background – pale pink to colorless


  • The tap water should be hard and very slightly alkaline.
  • Areas which have acidic or soft tap water should use Scott’s tap water substitute. If this is too alkaline, it may be diluted.
  • The water wash is to remove eosin from connective tissues so that the eosinophil granules are the most prominent feature. A light pink background helps with orientation.
  • Adjust staining and washing times to obtain suitable results.

Safety Note

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