Dawes’ Trichrome
for Fetal & Endocrine Tissue

Solutions

Solution A-1
Hematoxylin, 10% in 95% ethanol	16	mL
Ethanol, 95%	64	mL
Glycerol	80	mL

Solution A-2
Ammonium ferric sulphate	24	g
Ferrous sulphate	24	g
Distilled water	100	mL

Solution A-3
Azophloxine	1.2	g
Chromotrope 2R	0.2	g
Acetic acid, glacial	1.2	mL
Distilled water	160	mL

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
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.

Method

1. Bring sections to water via xylene and ethanol.
2. Place into solution A for 4 minutes.
3. Wash with tap water.
4. Place in solution B for 3 minutes.
5. Wash with distilled water.
6. Dehydrate quickly with 2 changes of 95% ethanol.
7. Rinse with absolute ethanol.
8. Clear with xylene and mount with a resinous medium.

Expected results

• Nuclei  –  black
• Muscle  –  Orange-red
• Collagen  –  Blue

Notes

1. The author states that both working solutions are stable and can be made in bulk. Multiply the amounts given by 10.
2. The method is suitable for staining sections in bulk.
3. The method is suitable as a counterstain for aldehyde fuchsin as well as being a general trichrome.

 

Reference
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.