Dawes' Trichrome
for Fetal & Endocrine Tissue
Materials
Solution A-1
| Material | Amount | |
|---|---|---|
| Hematoxylin, 10% in 95% ethanol | 16 | mL |
| Ethanol, 95% | 64 | mL |
| Glycerol | 80 | mL |
Solution A-2
| Material | Amount | |
|---|---|---|
| Ammonium ferric sulphate | 24 | g |
| Ferrous sulphate | 24 | g |
| Distilled water | 100 | mL |
Solution A-3
| Material | Amount | |
|---|---|---|
| Azophloxine | 1.2 | g |
| Chromotrope 2R | 0.2 | g |
| Acetic acid, glacial | 1.2 | mL |
| Distilled water | 160 | mL |
Preparation of Working Solution A
- Make each A solution ensuring all solids are dissolved.
- Combine solutions A-1 and A-2 and mix well.
- Add solution A-3 to the combined solution.
Solution B
| Material | Amount | |
|---|---|---|
| Phosphomolybdic acid | 1.5 | g |
| Aniline blue or Methyl blue | 3 | g |
| Acetic acid, glacial | 1.5 | mL |
| Picric acid, sat. aqueous | 150 | mL |
| Distilled water | 160 | 450 |
Tissue Sample
5µ paraffin sections of Bouin’s picric-acetic-formalin fixed fetal tissue, or endocrine tissue fixed in the Bouin’s mixture, but without the acetic acid.
Protocol
- Bring sections to water via xylene and ethanol.
- Place into solution A for 4 minutes.
- Wash with tap water.
- Place in solution B for 3 minutes.
- Wash with distilled water.
- Dehydrate quickly with 2 changes of 95% ethanol.
- Rinse with absolute ethanol.
- Clear with xylene and mount with a resinous medium.
Expected Results
- Nuclei – black
- Muscle – Orange-red
- Collagen – Blue
Notes
- The author states that both working solutions are stable and can be made in bulk. Multiply the amounts given by 10.
- The method is suitable for staining sections in bulk.
- The method is suitable as a counterstain for aldehyde fuchsin as well as being a general trichrome.
Safety Note
Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.
References
- Dawes, R. L. F., (1972),
A simple connective tissue stain suitable for foetuses and endocrine organs.
Medical Laboratory Technology, v. 29, Nº 1, p.27.
