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McFarlane’s Trichrome 1st Variant for Muscle and Collagen

McFarlane's Trichrome 1st Variant

for Muscle and Collagen



  • Weigert’s iron hematoxylin or equivalent
  • Solution A
    Picric acid0.2g
    Acid fuchsin1g
    Aniline blue2g
    Phosphotungstic acid1g
    Acetic acid, glacial2mL
    Distilled water98mL
  • Solution B
    Acetic acid, glacial2mL
    Distilled water100mL
  • Solution C
    Picric acid0.25g
    Phosphotungstic acid2.5g
    Ethanol, 95%10mL
    Distilled water90mL

Tissue Sample

5µ paraffin sections of neutral buffered formalin fixed tissue are suitable. Other fixatives are likely to be satisfactory. Most trichrome stains benefit from picric acid or mercuric chloride fixation. Formalin fixed tissues may benefit from secondary fixation of sections in Bouin’s fluid.


  1. Bring sections to water via xylene and ethanol.
  2. Stain nuclei with Weigert’s iron hematoxylin or equivalent.
  3. Place into solution A for 5 minute.
  4. Rinse with solution B.
  5. Rinse with distilled water.
  6. Place into solution C until differentiated.
  7. Rinse with distilled water.
  8. Wash with solution B.
  9. Dehydrate with ethanol.
  10. Clear with xylene and mount with a resinous medium.

Expected Results

  • Nuclei  –  black
  • Erythrocytes  –  yellow
  • Muscle  –  red
  • Cytoplasm  –  red
  • Collagen  –  blue


  • McFarlane also published two other, multi-step, trichrome methods. One is simpler than the other.
  • Solutions A and C require dry weights of picric acid. This could be provided from a saturated aqueous solution (1 g in 78 mL). Alternate formulas are:

    Solution A

    Picric acid, sat. aqueous16mL
    Distilled water82mL
    Acetic acid, glacial2mL
    Acid fuchsin1g
    Aniline blue2g
    Phosphotungstic acid1g

    Solution C

    Picric acid, sat. aqueous20mL
    Distilled water70mL
    Ethanol, 95%10mL
    Phosphotungstic acid2.5g

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.
    McFarlane, (1944)
    Stain Technology, v. 19, pp. 29