Polyester Wax Processing
In Peterfyi’s technique, the celloidin is more than just a glue to stick the tissue pieces together. It also supports it in the sense of protecting it from the harsh effects of hot paraffin. The double embedding sequence results in less shrinkage than paraffin alone, but not as little as celloidin alone. It is, however, considerably faster.
Formula
Steedman Variant
| Material | Amount | |
|---|---|---|
| Polyethylene glycol 400 distearate | 900 | g |
| 1-Hexadecanol | 100 | g |
Sage Variant
| Material | Amount | |
|---|---|---|
| Polyethylene glycol 600 distearate | 900 | g |
| 1-Hexadecanol | 100 | g |
Preparation Procedure
- Melt ingredients together at 65°C and stir well.
- Store unmelted, and only melt sufficient for use as needed.
- Do not keep molten for long periods.
- Protect from moisture.
Processing Schedule
- Fix tissues as wished.
- Bring tissues to 96% ethanol using graded ethanols.
- Place into an equal parts mixture of 96% ethanol and polyester wax.
A more gradual infiltration may be used for delicate tissues. - Place into pure polyester wax, two baths at 38°C.
Only melt sufficient wax for use at the time.
Do not keep the wax molten longer than necessary. - Cast, using Leuckhart’s molds or paper boats.
- Do NOT cool in water!
- Handle the blocks with forceps as the human hand is warm enough to soften the wax.
Safety Note
Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.
References
- Steedman, H.F., (1960)
Section cutting in microscopy
Blackwell Scientific Publications, Oxford, UK. - Sage, M., (1972)
Polyethylene glycol distearate 600 with 10% 1-hexadecanol: A superior embedding wax for warm climates.
Biotechnic and Histochemistry, v. 47, pp. 313-315
