College of Veterinary Medicine

Microorganisms

Gram

• Gram-positive organisms—blue to blue-violet
• Gram negative organisms—red
• Background—yellow

Back

Giemsa

• Bacteria—blue
• Nuclei—blue
• Cytoplasm—pale blue
• Rickettsias—reddish purple
• Erythrocytes—yellowish pink

Back

Ziehl-Neelsen

• Acid-fast bacteria—bright red
• Other tissue elements—according to counterstain (blue or yellow)

Back

Fites

• Atypical mycobacteria—bright red
• Other tissue elements—blue

Back

Warthin Starry

• Bacteria (spirochetes, helicobacter)—black
• Background—pale yellow to tan

Back

Steiner

• Bacteria (spirochetes, legionella)—black
• Background—pale yellow

Back

Gimenez

• Chlamydia—red
• Background—green

Back

PAS (Periodic Acid-Schiff's)

• Simple polysaccharides, neutral mucosubstances, basement membranes, mucolipids and fungus—magenta
• Background—according to counterstain

Back

GMS (Grocott Methenamine-Silver)

• Fungi—sharply delineated in black
• Pneumocystis—black
• Mucin—dark gray to black
• Background—green

Back

Connective Tissue

Wilder's Reticulum

• Reticulum fibers—black
• Background—pale pink

Back

Gordon-Sweet

• Reticulin—black
• Background—according to counterstain

Back

Masson's Trichrome

• Nuclei—black
• Cytoplasm, muscle, keratin—red
• Collagen—according to counterstain (blue or green)

Back

Jones'

• Reticular fibers and basement membranes—black
• Other tissue elements—according to counterstain

Back

PTAH

• Nuclei—blue
• Cytoplasm—blue
• Collagen—brown-pink
• Fibrin—blue
• Elastic fibers—purple
• Striated muscle fibers—blue
• Neuronal and glial cell processes—blue-purple

Back

Verhoeff's Elastic

• Elastic fibers—black
• Nuclei—blue to black
• Collagen—red
• Other tissue elements—yellow

Back

Minerals

Rhodanine

• Copper—red yellow
• Nuclei—light blue

Back

Von Kossa

• Calcium deposits—black
• Background—pink

Back

Perl's Iron (Prussian Blue)

• Iron deposits—brilliant blue
• Background—pink

Back

Carbohydrates

PAS (Periodic Acid-Schiff's)

• Simple polysaccharides, neutral mucosubstances, basement membranes, mucolipids and fungus—magenta
• Background—according to counterstain

Back

Alcian-Blue

• Sulfated mucosubstances—blue
• Background—according to counterstain

Back

Congo Red

• Amyloid deposits—pink to red
  • Note: Amyloid will show an apple-green birefringence when polarized
• Nuclei—blue

Back

Nerve Tissue

Cresyl Echt Violet

• Nissl substance—blue

Back

Bielschowsky's

• Axons—black
• Intracellular neurofibrils—black

Back

PTAH

• Neuronal and glial cell processes—blue-purple

Back

Luxol Fast Blue

• Myelin sheath—blue-green
• Background—according to counterstain

Back

Miscellaneous

Osmium

• Lipid—black

Back

OFG (Pituitary)

• Acidophils—orange-yellow
• Basophils—magenta-red
• Chromophobes—pale green
• RBS's—yellow

Back

Churukian Schenk

• Argyrophil and argentaffin cells—black
• Nuclei—orange to red
• Background—light yellow

Back

Toluidine Blue

• Mast cells—deep reddish purple
• Background—faint blue