Staining of histological slides.

1. Staining of Histological Slides
Presented by: NOOR ul EZA
College Roll # 896
University Roll #028748
BS (Hons) ZOOLOGY 6th Semester
Submitted to : Dr. SAGHIR AHMAD

2. Staining of Histological Slides
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

3. Histological slides
The small size of cell and matrix content make the study of tissues dependent on
Microscope and other biological techniques.
The most widely used method of studying tissue is using Histological Slides.
The Aim of good Histological technique is to preserve microscopic anatomy of tissue.
The Tissue in the slide must reflect the actual nature of the tissue in the body.

4. Techniques for Preparation
These Techniques are:
1) Fixation
2) Dehydration
3) Cleaning
4) Embedding
5) Cutting
6) Staining

5. Classification of Stains
1) Acid dyes stain basic components e.g. Eosin stains cytoplasm.
2) Basic Dyes stain acid component is colored and the basic
component is colorer colorless e.g. Basic Fuchsin stains nucleus.
3) Neutral dye is formed by combination of acidic and basic dyes it
gives different colours to cytoplasm and nucleus simultaneously.

6. Stains for Histological Slides
Hematoxylin and Eosin (H & E) used for histological slides
H & E is a charge-based stain
Hematoxylin stains acidic molecules shades of blue.
Eosin stains basic materials shades of red, pink and orange.

7. Staining Procedure
1) Deparaffinize and hydrate to water
2) If sections are Zenker-fixed, remove the mercuric chloride crystals
with iodine and clear with sodium thiosulphate
3) Mayer's hematoxylin for 15 minutes
4) Counterstain with eosin from 15 seconds to 2 minutes depending on
the age of the eosin, and the depth of the counterstain desired

8. .
5) Dehydrate in 95% and absolute alcohols, two changes of 2
minutes each or until excess eosin is removed
6) Clear in xylene, two changes of 2 minutes each
7) Mount in Permount or Histoclad