Sample type required: Deparaffinized and re-hydrated tissue sections on positively charged slides.
Fixative: 10% NBF
Step | Reagent | Time | Technical Notes |
1 | Weigert's iron hematoxylin working solution: ½ solution A (hematoxylin and 95% alcohol) and ½ solution B (distilled water, hydrochloric acid, and 29% ferric chloride solution) | 7 minutes | Be careful not to overstain with hematoxylin, as this can obscure the carminophilic tissue elements. If Gills hematoxylin is used in place of Weigert's iron hematoxylin, the mucin may have a bluish cast. |
2 | Running tap water | 10 minutes |
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3 | Working mucicarmine solution: 10 mL mucicarmine stock solution and 40 mL distilled water | 60 minutes | Stock mucicarmine should be stored refrigerated to slow down deterioration of the solution. Expiration of the solution should be closely monitored. Do not freeze solution to avoid frequent freeze-thaw cycles that may cause deterioration. |
4 | Distilled water | 1-2 changes |
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5 | Metanil yellow: 0.25% solution | 30 seconds to 1 minute | Be careful no to overstain with metanil yellow, as this can obscure carminophilic tissue elements. Tartrazine can be used in place of metanil yellow. |
Expected results:
- Mucin = Deep rose red
- Capsule of Cryptococcus = Deep rose red
- Nuclei = Black
- Other tissue elements = Blue or yellow
Post staining procedure:
Tissue sections should be rinsed well in distilled water, dehydrated with 95% alcohol, followed by 100% alcohols, cleared with xylene (or xylene substitute), and cover-slipped.
Procedural notes:
Mucicarmine stock solution should be stored refrigerated. Room temperature storage will accelerate the chemical breakdown of the solution. Frozen storage is not recommended to avoid repeated freeze-thaw cycles that may also affect the chemical reactivity of the stain.