Engel & Cunningham's Trichrome
for Muscle Fibres, Types I & II
Materials
- Harris alum hematoxylin
- Solution A
Material Amount Chromotrope 2R 0.6 g Fast green FCF 0.3 g Phosphotungstic acid 0.6 g Acetic acid, glacial 1 mL Distilled water 99 mL Adjust to pH 3.4 with 1N NaOH.
- Solution B
Material Amount Acetic acid, glacial 0.2 mL Distilled water 100 mL
Tissue Sample
Unfixed frozen sections of liquid nitrogen quenched muscle. Sections should be 5-10µ in thickness. The fibres should be in cross section, as close to a right angle to their length as possible.
Protocol
- Cut cryostat sections and dry at room temperature.
- Stain nuclei with Harris’ hematoxylin for 5 minutes.
- Rinse well with distilled water.
- Place into solution A for 10 minute.
- Rinse with solution B for a few seconds to differentiate.
- Dehydrate with ethanol.
- Clear with xylene and mount with a resinous medium.
Expected Results
- Nuclei – blue
- Type I fibres – green with a red cast
- Type II fibres – green
Notes
- Both fibre types are green overall, but type I fibres contain more red staining granular material and have a red cast.
- This is a modification of Gomori’s trichrome.
Safety Note
Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.
References
- Culling C.F.A., (1974)
Handbook of histopathological and histochemical techniques, Ed. 3
Butterworth, London, UK.
Citing:
Engel & Cunningham, (1963)
Rapid examination of muscle tissue.
An improved trichrome method for fresh frozen biopsy specimens.
Neurology, vol.13, pp.921
