
Key points in Hematoxylin and Eosin staining
- Hematoxylin is extracted from the heartwood of the tree Hematoxylin campechianum.
- Hematoxylin is not a stain itself. Hematin, a major oxidation product of hematoxylin is responsible for the color.
- Hematin is produced in two ways (a) Natural oxidation OR Ripening (b) Chemical oxidation.
- Ripening is done by exposing the solution to light and air. This is a slow process and takes up to 3-4 months.
- Ehrlichโs hematoxylin and Delafieldโs hematoxylin are obtained by natural oxidation.
- A mordant is a substance, usually a metal which helps bind the dye with the tissue strongly.
- Sodium Iodate is the mordant used in Meyerโs hematoxylin and Mercuric Oxide used in Harris hematoxylin.
- Aluminum is the most common mordant.
- Carraziโs hematoxylin has a staining time of 1 minute- shortest time for any hematoxylin stain. Hence it is used to stain frozen section slides.
- Iron hematoxylins are preferred connective tissue stains. Due to the acidity of dye solutions in connective tissue staining ( picric acid in Van Gieson staining), standard alum hematoxylins are decolorized. Iron hematoxylins such as Wiegert’s hematoxylin are resistant to the acidic environment and should be used in these techniques
Examples of ALUM HEMATOXYLIN are:
1. Erhlich hematoxylin
2. Delafield hematoxylin
3. Meyer hematoxylin
4. Harris hematoxylin
5. Cole hematoxylin
6. Carraziโs hematoxylin.
Check out this post on Carbohydrate staining.
Examples of IRON HEMATOXYLIN are
1. Weigertโs
2. Heidenhainโs
3. Loyez for myelin
4. Verhรถeffโs for elastin fibers.
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