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Mitchell’s Alum Hematoxylin

Mitchell's Alum Hematoxylin

6
steps
4
materials

Mitchell’s formula is from 1883 and is now obsolete. It does, however, show how Alum hematoxylin solutions were originally prepared, and the variability inherent in the procedures for doing so. The modern formula should stain satisfactorily.

Materials

Original Formula

MaterialAmountFunction
Logwood, ground2 ouncesDye
Potassium alum9 ouncesMordant
Distilled wateras neededSolvent
Glycerol4 fl. ouncesStabiliser

Compounding Procedures

  1. Moisten the ground logwood with water and pack it into a funnel.
  2. Pour water onto the wood until it comes through barely coloured.
  3. Remove the wood from the funnel, spread out and dry.
  4. Dissolve the Alum in 8 fluid oz of water.
  5. Moisten the logwood with some Alum water and pack it tightly into the funnel.
  6. Pour the rest of the Alum solution onto the logwood.
  7. When the first drops come through, seal up the tip of the funnel.
  8. Leave 48 hours for the dye to be extracted.
  9. Remove the seal and collect the fluid that comes through.
  10. Pour on more water until 12 fluid oz have been collected.
  11. Add the glycerol, mix well and filter.

Modern Formula

MaterialAmountFunction
Hematoxylin3 gDye
Potassium alum35 gMordant
Distilled water340 mLSolvent
Glycerol115 mLStabiliser

Compounding Procedures

  1. Dissolve the Alum in the water.
  2. Add the hematoxylin and mix until dissolved.
  3. Add the glycerol, mix well and filter.

Protocol

  1. Bring sections to water with xylene and ethanol.
  2. Place into the staining solution for a few minutes, or dilute 1:7 with distilled water and stain overnight.
  3. Rinse with water and blue.
  4. Rinse well with water.
  5. Counterstain if desired.
  6. Dehydrate with ethanol, clear with xylene and mount with a resinous medium.

Expected Results

  • Nuclei  –  blue
  • Background  –  as counterstain or unstained

Notes

  • The staining characteristics were not given, but it is likely progressive, especially when diluted. If overstaining does occur, differentiate with 0.5 – 1% hydrochloric acid in 70% ethanol.
  • The reason for the pre-wash of the logwood in water during the original preparation method was stated to be for the removal of tannin.
  • The amount of hematoxylin in the modern formula is based on the fact that logwood contains up to 10% of the dye. Two ounces (about 57g) could contain a maximum of about 6 grams of dye. A 50% extraction, or 3 grams hematoxylin has been allowed for. It could well have been more or less than this.
  • The original formula gives 255 grams of potassium Alum to dissolve in 227 mL water. It takes just over 7 mL water to dissolve 1 gram crystalline potassium alum, so the amount of water specified would be able to dissolve only about 32 grams.
  • Blueing is done with alkaline solutions such as hard tap water, Scott’s tap water substitute, 0.1% ammonia water, 1% aqueous sodium acetate, 0.5% aqueous lithium carbonate etc.

Safety Note

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

References

  1. Arthur Bolles-Lee, (1885)
    The Microtomist’s Vade-Mecum
    Originally published by: J & A Churchill, London, England.
    Republished by: Science Heritage Ltd., Lincolnwood, Illinois, USA.
  2. Susan Budavari, Editor, (1996)
    The Merck Index, Ed. 12
    Merck & Co., Inc., Whitehouse Station, NJ, USA
  3. Lemmens, R. H. M. J. and Wulijarna-Soetjipto, N., Editors. (1992)
    Plant resources of South East Asia No. 3,
    Dye and tannin-producing plants.
    PROSEA, Bogor, Indonesia.