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• Connective tissue


  One of the tissues of the body
• Nervous tissue


  One of the tissues of the body
• Skeletal muscle


  One of the tissues of the body
• Cardiac muscle


  One of the tissues of the body
• Histological technique deals with the preparation of tissue for microscopic examination
• Methods


  • Paraffin method
  • Freezing method
• Biopsy


  Piece of tissue or organ taken from living human being
• Autopsy


  Piece of tissue or organ taken from dead body
• Fluid specimens


  • Blood
  • CSF
  • Ascites fluid
  • Pleural effusion fluid
• How to study the specimen

  • Gross: colour, size, surface, texture, consistency
  • Microscopical examination: examine under microscope
• Paraffin method techniques


  • Fixation
  • Dehydration
  • Clearing
  • Embedding
  • Sectioning (Cutting)
  • Staining
• Fixation

  The process by which cells and tissue are fixed in a physical and chemical state so that they will withstand subsequent treatment with various reagents with minimum loss of architecture
• Dehydration


  The process of pulling the water from the sample, carried out by using alcohol in various dilutions
• Clearing


  The step done by using Xylol or Chloroform
• Impregnation


  The process of allowing the tissue to be impregnated with paraffin wax at its melting point temperature of 54-60°C
• Sectioning


  The process of trimming the paraffin block and cutting thin sections of 5 μm thickness using a rotary microtome
• Microtomy is a tool used to cut extremely thin slices of material, known as sections, for microscopy
• Staining with Hematoxylin-Eosin (H&E)


  1. Xylene

  2. Alcohol 70%

  3. Alcohol 90%

  4. Alcohol absolute

  5. Hematoxylin

  6. Wash with tap water

  7. Eosin

  8. Wash with tap water

  9. Dry in oven

  10. Clear with xylene and mount with Canada balsam
• Frozen section biopsy


  Used for spot diagnosis, using fresh unfixed tissue cut at -20 to -30°C in a cryostat machine
• Hematoxylin


  Basic dye that stains acidic structures (basophilic) like nucleus and ribosomes
• Eosin


  Acidic dye that stains basic structures (acidophilic/eosinophilic) like mitochondria, collagen fibers and muscle fibers
• H&E stain gives the nucleus a blue color and the cytoplasm & extracellular matrix a pinkish color
• Special stains


  Any staining other than H&E, used to visualize particular tissue structures, elements, or microorganisms
• Special stains


  • Masson's trichrome (for collagenous connective tissue)
  • Periodic acid-Schiff (PAS) (for carbohydrate-rich structures)