Skip to main content

Taenzer-Unna Orcein for Elastic Fibres

Taenzer-Unna Orcein

for Elastic Fibres



Orcein solution

Ethanol, 70%100mL
Hydrochloric acid, conc.1mL

Acid ethanol

Ethanol, 70%100mL
Hydrochloric acid, conc.1mL

Tissue Sample

5µ paraffin sections of neutral buffered formalin fixed tissue are suitable. Other fixatives are likely to be satisfactory.


  1. Bring sections to water via xylene and ethanol.
  2. Rinse with 70% ethanol.
  3. Place into orcein solution for an appropriate time.
  4. Optionally, treat with acid ethanol until collagen is unstained (a few seconds).
  5. Wash with water
  6. Counterstain if wished.
  7. Dehydrate with 95% and absolute ethanols.
  8. Clear with xylene and mount with a resinous medium.

Expected Results

  • Elastic fibres  –  purplish brown
  • Other tisse  –  as counterstained


  • Gray specifies 0.8 grams orcein, most others specify 1 gram.
  • Gray specifies 50% ethanol, Culling 70% and Carleton 80%. Others have recommended concentrations ranging from 65% to 100% (Lillie).
  • Staining times specified include 6-12 hours (Gray), overnight (Culling) and 30 minutes to 2 hours (Carleton).
  • Elevating the temperature (37°C Carleton, 56°C Culling) decreases staining time.
  • Recommended counterstains are van Gieson, methylene blue, H&E.

Safety Note

Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.


  1. Gray, Peter. (1954)
    The Microtomist’s Formulary and Guide.
    Originally published by: The Blakiston Co.
    Republished by: Robert E. Krieger Publishing Co.
    von Kahlden, C., and Laurent, O. (1896)
    Technique microscopique.
    Carré, Paris, France
  2. Drury, R.A.B. and Wallington, E.A., (1980)
    Carleton’s histological technique Ed. 5
    Oxford University Press, Oxford, UK.
  3. Culling C.F.A., (1974)
    Handbook of histopathological and histochemical techniques Ed. 3
    Butterworth, London, UK.
  4. Mallory, F. B. & Wright, J.H., (1904)
    Pathological technique, Ed.3
    W. B. Saunders, Philadelphia, USA.
  5. Lillie, R.D., (1954)
    Histopathologic technique and practical histochemistry Ed.2
    Blakiston, New York, USA.