2. Content
• Introduction
• General principles of staining (theory )
• Theory of staining
• Method of H & E staining
• Theory of H & E staining
• Types of hematoxylin
3. Introduction
Colors are beyond the expression
But helps to know things, differentiate & express ,
particular
entity
Same is applicable to histopathology ……….
4. Why to stain
• The purpose of staining is that of outlining the
tissue and cellular components
To identify tissue
To establish the presence or absence of disease
processes.
5. Most commonly used stains
Histopathology – Routine Hematoxylin(H)
Eosin(E),
In microbiology – Gram’s Method and Ziehl-
Neelson’s method,
In hematology- Romanowsky stain ,
In cytopathology -Papanicoloau stain.
6. Some important terminology
• Basophilic- The entities stainable with basic dye &
are substances which are usually acidic in nature.
• Acidophilic- The entities stainable with acidic dye &
are substances which are usually basic in nature.
• Sudanophilic - The entities stainable with oil soluble
dyes e.g. sudan III, IV
7. • Argyrophilic- The entities stainable with silver
nitrate solution.
E.g. AgNOR
• Argentaffin- The entities staininable with silver
nitrate solutions without chemical reduction
procedures
• Neuroendocrine cells
• Metachromatic -The entities will stain in a color or
hue different from that of staining solution itself.
8. Definition
Stains:
Stains are chemical substances used to achieve visible color contrast
in the microscopic picture of a prepared tissue.
Staining:
Staining may be loosely defined as treating tissue or cells with a
reagent or series of reagents so that it acquires a color; usually, no
particles of dyes are seen and the stained element is transparent.
9. DYES
These are essentially aromatic benzene ring compoundsor
derivatives that possess the twin properties of color and
ability to bind to tissue.
10. Classification
According to the origin of a dye.
1)Natural
e.g. hematoxylin, Carmine, and Saffron
2)Synthetic
e.g. Benzene, toluene, and naphthalene or phenols
11. According to their affinity for certain tissue components.
Acidic dyes
Acid dyes usually stain basic components such as cytoplasm,
acidophil granules etc.
e.g. Eosin, Acid fuchsin
Basic dyes
Usually stain acidic stain acidic components such as nucleus,
basophil granules etc.
e.g. Hematoxylin, Basic Fuchsin, Methylene blue.
Neutral dyes
These consist of mixtures of basic and acidic dyes.
Both cations and anion contain chromophoric groups and
both have colored
radicles.
e.g. Romanowsky dyes formed by the interaction of
polychrome methylene blue
and eosin.
