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
- Heamatoxylin and Eosin are most common
Types of stains - Reaction of stain: - Acidic
- Basic - Neutral
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
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
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