CYTOLOGY BY Dr. TAREK ATIA Histology and Cell Biology

BOOK Color Textbook of Color Textbook ofHistology 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 - Buffered formol saline - 10% formalin - 10% formalin - Suza, Bouin, Zenker solution - Suza, Bouin, Zenker solution - Formaldehyde or Glutradhyde - Formaldehyde or Glutradhyde - Osmium tetraoxide - Osmium tetraoxide - Potassium permanganate - 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 paraffin - Tissues are impregnated in Epon in gelatin capsule. - Tissues are impregnated in Epon in gelatin capsule. 5- Cutting: - Paraffin block are cut by microtome using metal knife, into thin sections ~ 6µ - Paraffin block are cut by microtome using metal knife, into thin sections ~ 6µ - Capsules are cut by ultra-microtome, using glass or diamond knife, into ultra thin sections nm. - Capsules are cut by ultra-microtome, using glass or diamond knife, into ultra thin sections nm.

6- Mounting: - Sections spread on the hot plate and mounted on glass slides. - Sections spread on the hot plate and mounted on glass slides. - Sections mounted on metal grids. - Sections mounted on metal grids. 7- Staining: - Variable stains are used for specific tissues. - Variable stains are used for specific tissues. - Stained by heavy metals like lead nitrate and uranyl acetate. - 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 Eosin stain - Acidic Eosin stain - Basic Heamatoxylin stain - Basic Heamatoxylin stain - Neutral Leishman stain - Neutral 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 - Phase contrast microscope - Polarizing microscope - Fluorescence microscope - Electron microscope: Scanning / Transmission - Interference microscope - Confocal microscope - Inverted 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

Histology and Cytology

Course of Histology - Cytology: Cell, Nucleus, DNA, and Cytogenetics. - Tissues: 4 basic tissues including; Epithelium, Connective (Cartilage, Bone, Blood), Muscular, and Nervous tissues. - Body systems and different Organs.