von Orth’s Fluid
Formula
Stock von Orth’s base
Material | Amount | |
---|---|---|
Potassium dichromate | 22.4 | g |
Potassium sulphate | 9 | g |
Distilled water | 900 | mL |
Working von Orth’s fluid
Material | Amount | |
---|---|---|
Stock von Orth’s base | 90 | mL |
Formalin, concentrated | 10 | mL |
Make solution just before use.
Description
Dichromate formalin mixtures such as Orth’s fluid are unstable and deteriorate, so they must be made just before use. This is conveniently done by keeping a stock solution and adding formalin to it immediately before the tissue is placed into it. Gray recommends thet fixation be carried out in the dark and that the dichromate be washed out with a dilute formalin solution, also in the dark. Presumably, this is because dichromate can be photosensitive under some circumstances.
Time
Generally, one or two day’s fixation for normal slices of tissue should be satisfactory.
Aftertreatment
Wash well with running tap water or dilute formalin in the dark to remove excess dichromate.
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:
Orth, (1896)
Zietschrift für wissenschaftliche Mikroskopie und für mikroskopische Technik, Leipzig