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CYTOLOGY BY Dr. TAREK ATIA Histology and Cell Biology


BOOK Histology, part I & II Zakaria Abdel Hameed

Color Textbook of Histology Leslie P Gartner James L Hiatt


- Micro-techniques for tissue preparation.

- Stains. - Microscopes. - Special techniques used for medical diagnosis.

- Cell, Tissues and Organs.


Micro-techniques for tissue preparation - Using Light or Electron Microscope. 1- Fixation:- Buffered formol saline - 10% formalin - Suza, Bouin, Zenker solution - Formaldehyde or Glutradhyde - Osmium tetraoxide - Potassium permanganate


2- Dehydration: Gradual removal of water from the tissue using ascending grads of

ethyl alcohol to prevent tissue shrinking.

3- Clearing: Replacement of alcohol in tissue by

clearing fluid like xylen, benzene, or acetone


4- Embedding: - Tissues are impregnated in paraffin - Tissues are impregnated in Epon in gelatin capsule. 5- Cutting: - Paraffin block are cut by microtome using metal knife, into thin sections ~ 6Âľ - Capsules are cut by ultra-microtome, using glass or diamond knife, into ultra thin sections 50-100nm.


6- Mounting: - Sections spread on the hot plate and mounted on glass slides. - Sections mounted on metal grids. 7- Staining:

- Variable stains are used for specific tissues. - Stained by heavy metals like lead nitrate and uranyl acetate.


Stains - Special dyes used to stain the histological sections and make them ready for

microscope examination.

- Heamatoxylin and Eosin are most common

used.


Types of stains - Reaction of stain: - Acidic

- Basic - Neutral

Eosin stain

Heamatoxylin stain Leishman stain

- Physical stain: stain dissolve in tissue without any chemical reaction such as - SUDAN III for fatty tissues.


- Vital stain: Staining living tissue inside the body.

Trypan blue stain.

- Supravital stain: Staining living tissues outside

the body.

Brilliant cresyl blue.

- Metachromatic stain: Staining the tissues with a color different from the original color of stain.

Toluidin blue staining of Mast cells.


- Polychromatic stain: Staining the tissues with multiple colors in spite of using a single stain. Geimsa stain for blood. - Orthocromatic stain: Staining the tissues with the same color of the stain, such as H&E. - Histo-chemical stain: Staining the different chemical components of the cell. - Immuno-histo-chemical stain: Localisation and staining specific proteins by the antigen antibody reaction.


MICROSCOPY - Light microscope

- Electron microscope: Scanning / Transmission

- Phase contrast microscope - Interference microscope

- Polarizing microscope

- Confocal microscope

- Fluorescence microscope

- Inverted microscope


Light microscope


Light microscope

Electron microscope


Special techniques used for diagnosis - Histchemistry - Immunohistochemistry - Tissue / Cell Culture - Cell Fractionation - Exfoliative Cytology - Cytogenetics and Molecular Cytogenetics

- Bone Marrow smear / Blood film - Fine needle aspiration / biopsy

- Flowcytometry

- Autoradiography


Cell fractionation


1- Introduction