STAINING IN MICROBIOLOGY & PATHOLOGY S/N STAIN (DYE) MATERIAL STAINED + COLOUR EXAMPLE

1 H&E (Hematoxylin & Eosin) Nucleus-BLUE, Cytoplasm-RED General Tissue Stain

2 Gram (aka B&B or B&H)

[Crystal violet, iodine, acetone, carbol fuschin]

Gram +ve BLUE Gram -ve RED

3 Ziehl Neelsen (Full) [Methylene Blue

Counter stain] Acid-Fast Organisms RED Mycobacterium

4 Ziehl Neelsen (Modified) [Malachite

Green Counter stain] Acid-Fast Organisms Norcarda

5 PAS (Periodic acid-Schiff) Glycogen & Proteoglycan-

MAGENTA Descemet Membrane; FUNGI

6 GMS (Gomori methenamine silver) Fungal elements: BLACK FUNGI e.g Fusarium

7 Alcian Blue Acid Mucopolysaccharide BLUE Carvenous Optic atrophy

8 Colloidal Iron Acid Mucopolysaccharide BLUE Macular Dystrophy

9 Oil red O Lipid

10 Congo Red Amyloid ORANGE Lattice Dystrophy

11 Crystal violet Amyloid PURPLE, VIOLET Lattice Dystrophy

12 Thioflavin T (Th T) Amyloid YELLOW Lattice Dystrophy

13 Alizian Red Calcium RED Band keratopathy

14 Von Kossa Calcium Phosphate salts BLACK Band keratopathy

15 Perls Prussian Blue Iron BLUE Hemosiderosis Bulbi

16 Masson Trichrome Collagen BLUE Granular dystrophy

17 Masson Trichrome Muscle RED Red Deposits

18 Verhoeff-van Gieson Elastic Fibres BLACK Temporal artery elatic layer

19 Giemsa Bacteria; Inflammatory cells Exfoilative Cytology

20 Hansel (eosin + methylene blue) Eosinophils Exfoilative Cytology

FIXATIVES USED IN PATHOLOGY 1. Formalin (10% neutral buffered Formalin): [Colour: Clear]

Most commonly used fixative

40% solution of Formaldehyde in water

Stabilizes protein, lipid and carbohydrates

Prevents post-mortem enzymatic destruction of tissue (autolysis)

Diffuses quickly through tissue (diffuses @ a rate of 1 mm/hr)

For adequate fixation, tissue is suspended in formalin in a Volume of 10:1 for at least 24 hrs

2. Glutaraldehyde: – Electron Microscopy [Colour: Clear]

3. Ethyl Alcohol: – Cytologic Preparations [Colour: Clear]

4. Michel Medium: – Immunofluorescence Studies [Colour: Light Pink]

5. Bouin Solution: – Small Biopsies [Colour: Yellow]

6. B5: – Lymphoproliferative tissue (e.g. Lymph node) [Colour: Clear]

7. Ethanol/Methanol: – Crystals (e.g. Urate Crystals of gout) [Colour: Clear]

8. Zenker Acetic Fixative: – Muscle Differentiation [Colour Orange]

TISSUE PROCESSING IN PATHOLOGY ALCOHOL – Dehydrating agent (removes water) XYLENE – Clearing agent (to replace alcohol) PARAFFIN – Infiltrating/Embedding agent

– mechanically stabilizes tissue making it possible to be cut into sections © Dr. Edoga C. E.