Masson Trichrome
Classification: connective tissue stain
Mechanism of staining: porosity
Purpose: stain collagen
Control tissue: skin, intestine
Properly Stained Slide
Grey/black: Nuclei
Bright red: Muscles, RBC
Dull red: Cytoplasm
REAGENT |
PURPOSE |
MECHANISM OF STAINING |
SOURCE OF ERROR |
Iron Hx (Weigert’s) |
Nuclear stain |
Ionic bonding |
Omitted: No nuclear staining. |
Too short: Since it is a progressive stain,
do not perform the differentiating step. |
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Too long: Not an issue- can be corrected at a later step with
a differentiator. |
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Ponceau 2R |
Stains acidophilic tissues |
Porosity |
Omitted: Nuclei and cytoplasm will not be demonstrated. |
Too short: Nuclei and cytoplasm will not be demonstrated or
weakly stained. |
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Too long: Will obscure the target tissue. |
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Phospho-myolybdic acid |
Used as a differentiator. Acts to remove acid fuchsin from
collagen fibers. Works to trap acid fuchsin in RBC, muscle & cytoplasm. |
Porosity |
Omitted: Light green counterstain will enter
the target muscle. |
Too long: Acid fucshin will be removed from
the muscle components. |
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Too short: Light green secondary
counterstain will entre the muscles. |
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Light green |
Stains collagen fibers. Works as a counterstain. |
Salt linkage and porosity |
Omitted: Collagen will not be demonstrated. |
Too long: Counterstaiin will appear dark and
may interfere with the staining of muscles. |
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Too short: Collagen will be stained pale. |
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Acid alcohol |
Removes excess counterstain |
|
Omitted: Without acid alcohol there will be
an excess of background staining which will obscure the nuclear detail. |
Too long: No nuclear detail will be present
since the tissue is now overdifferentiated. |
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Too short: Since this step only includes one
dip the alternative is no dips and that would result in no nuclear detail. |
References
Officer B. HIML251 Lecture notes: Alcian Blue and Masson Trichrome stains, January 28, 2009