Helly’s Fluid
Formula
Stock Helly’s base
Material | Amount | |
---|---|---|
Mercuric chloride | 49.2 | g |
Potassium dichromate | 20 | g |
Sodium sulphate | 10 | g |
Distilled water | 960 | mL |
Working Helly’s solution
Material | Amount | |
---|---|---|
Stock Helly base | 48 | mL |
Formalin, concentrated | 2.5 | mL |
Make just before use.
Description
This is a good routine fixative giving excellent cytoplasmic preservation, although it is not used as much as it was in the past due to the mercuric chloride content.
It should be noted that the stock Helly’s base solution is identical to that of the stock Zenker’s base solution and is a fixative in its own right, giving good cytoplasmic preservation.
Time
Small, thin, pieces of tissue will be fixed in a few hours. Three millimeter thick slices will require overnight.
Aftertreatment
Wash well with running tap water to remove excess dichromate. Treat sections with the iodine thiosulphate sequence to remove mercury pigment.
Safety Note
Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.
References
- Gray, Peter. (1954)
The Microtomist’s Formulary and Guide.
Originally published by: The Blakiston Co.
Republished by: Robert E. Krieger Publishing Co.
Citing:
Helly, (1903)
Zietschrift für wissenschaftliche Mikroskopie und für mikroskopische Technik, Leipzig
Most reference texts contain a variant of this solution under the Helly name, although the amount of each ingredient may be slightly different.