|Stock Helly's base|
|Working Helly's solution|
|Stock Helly base||48||mL|
Make just before use.
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.
Small, thin, pieces of tissue will be fixed in a few hours. Three millimetre thick slices will require overnight.
Wash well with running tap water to remove excess dichromate. Treat sections with the iodine thiosulphate sequence to remove mercury pigment.
Due to its mercuric chloride content this fixative will corrode metal. Metal cassettes, metal jar lids, metal forceps, metal rulers, metal countertops and all other metal objects must be avoided. This includes stainless steel, which may resist corrosion better than other metals but will still be affected. Dry paper towels are an effective barrier. Do not forget to dispose of them safely.
Gray, Peter. (1954)
The Microtomist's Formulary and Guide.
Originally published by:– The Blakiston Co.
Republished by:– Robert E. Krieger Publishing Co.
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.