ZENKER'S FLUID/FIXATIVE

 

 

Potassium dichromate
2.5 g
Mercuric chloride
6.0 g
Distilled water
100 ml
Acetic acid, glacial (add just before use)
5.0 ml


Dissolve the potassium dichromate and mercuric chloride in the water while heating. Use small pieces of tissue: 2 cm square or rectangle, not more than 2-4 mm thick). Fix 6-8 hours; longer times will make tissue brittle and difficult to section. Wash off excess fixative with running water at least l~ hours. After fixation and washing, tissue may be stored in 70% EtOH. Remove mercuric chloride crystals before staining by immersing the slides in alcoholic iodine after the paraffin has been removed.

How to remove mercuric chloride crystals:

  1. Deparaffinize slides through xylene, 100% and 95% EtOH.
  2. Place in alcoholic iodine solution ( 0.5% iodine in 80% EtOH) for 5-10 minutes.
  3. Wash in water or rinse in 80% EtOH.
  4. Place in a solution of 5% sodium thiosulfate (hypo) for 2-5 minutes to bleach out the iodine.
  5. Wash thoroughly in running tap water (5 minutes) to remove the hypo.
  6. Stain