VAN 211: Veterinary Histology and Embryology (2+2)

PARAFFIN METHOD OF PREPARING TISSUE

• The Scheme given below refers to procedures commonly employed for routine preparations of histological sections.
• It should be noted that procedures may have to be considerably modified or additional new process introduced when other fixatives are used or special methods followed.
• The method given below deals with fixations, using formal saline, embedding in paraffin and staining by Heamatoxylin and eosin.
• Fixation in 100% Formal saline
• Washing in water
• Dehydration in ascending grades of
• 50%
• 70%
• 90%
• Absolute alcohol  (usually three changes)
• Clearing commonly in xylol (sometimes benzene, toluene, or cedar wood oil).
• Inclusion in paraffin embedding oven at 56^º to 60^ºC
  • Permeation with paraffin three changes
  • Casting of tissues (orientation and cooling the mass).
• Sectioning
• Sectioning (microtomy)
• Fixing section to slide
• Staining