Helly’s fluid fixation

Contributed by Martin Fitzpatrick, University of Birmingham, United Kingdom

Fixation using Helly’s fluid

• To prepare stock solution add 1l distilled water to suitable container.
• Add 25g potassium dichromate.
• Add 50g mercuric chloride.
• Add 10g sodium sulphate and mix thoroughly. Store stock solution until required.
• Make up fixative just before use.

Add 5ml formalin (40% aqueous solution of formaldehyde) to 100ml stock solution

• Fix tissues for 12-24 hours
• Wash fixed tissue for 24hours prior to processing

This method is based, with permission, on an original protocol available here.