French's Stain
for Elastic Fibres
Materials
- Weigert’s iron hematoxylin or equivalent
- Van Gieson’s picro-fuchsin
- French’s solution
Material Amount Basic fuchsin 1 g Crystal violet 1 g Resorcin 4 g Ferric chloride, 30% aqu. 25 mL Ethanol 95% 200 mL Distilled water 200 mL Hydrochloric acid, conc. 4 mL Preparation
- Add the dye and resorcin to the water in an oversize flask.
- Bring to the boil, and add the ferric chloride.
- Boil for 5 minutes.
- Cool and filter.
- Dry the filter paper and beaker. Place the precipitate and filter paper back into the flask.
- Add the ethanol and heat carefully until the precipitate dissolves.
- Add the hydrochloric acid.
- Restore to 200 mL with 95% ethanol.
Tissue Sample
5µ paraffin sections of neutral buffered formalin fixed tissue are suitable. Other fixatives are likely to be satisfactory.
Protocol
- Bring sections to water via xylene and ethanol.
- Place into French’s solution until adequately stained (may be overnight).
- Wash with 95% ethanol to remove excess solution.
- Differentiate with 1% acid alcohol.
- Wash in water.
- Counterstain with iron hematoxylin and van Gieson.
- Dehydrate with ethanol, clear with xylene and mount with a resinous medium.
Expected Results
- Elastic fibres – dark blue-green
- Collagen – red
- Cytoplasm – yellow
- Nuclei – blue
Notes
- This is Weigert’s iron resorcin fuchsin using crystal violet and basic fuchsin instead of basic fuchsin alone.
- It is usually recommended that the basic fuchsin should not be of the type that produces good Schiff’s reagent. That is, the basic fuchsin should contain more rosanilin than pararosanilin.
- The ferric chloride solution should be freshly made.
Safety Note
Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.
References
- Histological demonstration techniques, (1974)
Cook, H C.
Butterworths, London, England
