DEHYDRATION

DEHYDRATION

1. Water completely reduced by passing the tissue through dehydrating agents

2. water need to be removed and replace with xylene

   • 1 mm tissue-30 minutes each alcohol
   • 5mm tissue - 90 minutes each alcohol

3. Chemical

   • Ethanol
     • Rapid, efficient
     • prolonged immersion in absolute ethanol causes tissue to harden
   • Isopropanol
     • slightly slower
     • better lipid solvent
     • dehydrate hard, dense tissue
   • Butanol
     • poorly miscible
     • lightly chitinised arthropod and rodent tssue
   • Acetone
     • coagulant secondary fixative
     • fatty specimen
   • Methanol
     • harden tissue more in microwave processing