Fixation on Histology

Over the years, I have encountered numerous techniques to soften and section nail specimens.  This includes everything from soaking the exposed specimen in your water bath, different types of softening agents like solutions of potassium hydroxide and even a product like Nair.  One rarely mentioned, but very effective technique that that I learned many years ago from a colleague was direct exposure of the processed specimen to any type of hand/body lotion.  It works surprisingly well and without any damage to the structure of the specimen.  This is a step-by-step process of how it works:

1. Process the specimen in toto, as you would other small biopsies.
2. Embed the nail specimen/fragment on any edge. I have found that this helps facilitate the facing step and generally keeps it from “popping” from the paraffin block.
3. At the microtomy station, face into the block exposing the outermost surface of the nail specimen.
4. Place a small amount of hand/body lotion directly on the nail exposed surface for approximately 15-20 minutes. Time can vary based upon the size of the specimen and I have not experienced any harm to the specimen in allowing extra time.
5. Wipe away the excess lotion and place block on the cold plate/ice bath.
6. Section the block as you would any other specimen, taking care to get the first sections and not going back too deep into the block.
7. Place sections on some type of adhesive slide.
8. Dry slides and stain.

Good luck and share your results with this technique on NSH’s member’s only community.
-  The Block!
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Written by Carl Sagasser, HT(ASCP)