Histology labs can sometimes get some out of the ordinary specimens. If you’re used to solely dealing with soft tissues, you may be stumped when it comes to something like nails, which don’t behave exactly like a soft tissue, but also don’t have the same process as a bone.
To start, nails are not made of calcium, they’re made of keratin, so decalcifying them like you would a bone is not going to do the trick. The end goal however, of making the specimen softer remains, however. So how do you soften a nail?
There are several methods, one of which is the use of the household hair removal product, Nair. Before processing, soak the nail in Nair for about a day or two (depending on the thickness of the nail), when you take it out, it is easier to cut. Alternatively, you can soak the section in a dilute aqueous solution of potassium hydroxide (KOH) to de-keratinize it before processing. (Another tip, when embedding nail, embed on edge!)
You can also find pre-made vendor products that will achieve the same effect as Nair or potassium hydroxide; items such as Nail Prep, a softener specifically designed for use on nails.