List of Stains

Stain	Uses	Tissue Components Targeted		Mechanism of Staining	Stains Used Primary Secondary	Other Reagents	Controls
Hematoxylin & Eosin (H&E)	General tissue staining	Nuclei - blue RBCs - red/dark pink Muscle - pink Collagen - light pink			Harris Hematoxylin (nuclear) Eosin Y (cytoplasm)	Harris Hematoxylin Acid Alcohol Scott's tap water substitute Eosin Y
Periodic Acid-Schiff (PAS)	Identifying neutral polysaccharides (Group I carbohydrates) glycogen starches cellulose fungi (chitin)
Alcian Blue (AB)	Identifying acid mucopolysaccharides (Group II carbohydrates) Identifying glycoproteins (Group III carbohydrates)	pH 1.0: Sulfated mucopolysaccharides	pale blue	Ionic bonding
		Acid mucins (mucopolysaccharides)
		Sialomucins (glycoproteins)
		Background	pink/red
Alcian Blue + Periodic Acid-Schiff (AB PAS)	Identifying multiple different types of carbohydrate groups
Congo Red	Identifying amyloid deposits			Hydrogen bonding
Masson Trichrome	Identifying fibrotic tissue	Connective Tissue Stain Nuclei - blue-black RBCs - dark red Muscle - red Cytoplasm - red Collagen - varies by stain (often green or blue)		Porosity and ionic bonding	No primary stain. Iron hematoxylin (nuclear) Ponceau (dense connective) Light green or aniline blue (loose connective)
Gordon and Sweet's Reticulin	Identifies reticulin fibres (type III & IV collagen) Differential diagnosis of certain tumour types	Connective Tissue Stain Reticulin fibres - black Nuclei and cytoplasm - varies by counterstain		Metallic impregnation Argyophilic metallic impregnation & substitution Counterstain Ionic bonding	a Varies (light green, nuclear fast red, neutral red, etc.)
Verhoeff's Van Giesen	Identifies elastin fibres	Connective Tissue Stain Elastic fibres - blue-black/black Nuclei - dark blue-black Collagen - red Muscle - orange RBCs - yellow Cytoplasm - yellow		Van der Waal's Primary stain Porosity and ionic bonding Counterstain	Verhoeff's Iron Hematoxylin (elastic fibres) Van Giesen Picric acid (RBCs and cytoplasm) Acid fuchsin (collagen and muscle)
Oil Red O	Identifying triglycerides, lipids, and lipoproteins	Connective Tissue Stain		Selective solubility
Gram	Microorganism stain (gram +/- bacteria)	Microorganism Stain Gram positive - purple Gram negative - blue		Ionic bonding (differential)			Positive: appendix, tissues known to contain microorganisms
Ziehl-Neelsen

Gram Stain

• Staining technique: Differential staining (ionic bonding to cell wall)
• Primary Stain: Crystal violet
  • Targets: Gram positive bacteria (purple/blue)
• Counterstain: Safranin
  • Targets: Gram negative bacteria (pink/red)

Ziehl-Neelsen

• Staining technique: Differential staining/acid fastness (ionic bonding)
• Primary Stain:
  • Targets: Acid-fast bacteria (e.g., Mycobacteria)
• Counterstain:
  • Targets:

Grocott Methenamine Silver

• Staining technique:
• Primary Stain:
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• Counterstain:
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Perl's Prussian Blue

• Staining technique:
• Primary Stain:
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• Counterstain:
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Masson Fontana

• Staining technique:
• Primary Stain:
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• Counterstain:
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Von Kossa

• Staining technique:
• Primary Stain:
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• Counterstain:
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Jones Methenamine Silver

• Staining technique:
• Primary Stain:
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• Counterstain:
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Toluidine Blue

• Staining technique:
• Primary Stain:
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• Counterstain:
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