Dear collegues,

We have equipment for grinding hair samples and subsequently analyzing cortisol concentrations. Recently, we have begun exploring the feasibility of extending this methodology to fingernail samples. However, we have encountered a significant limitation: due to the greater hardness of nails compared to hair, the equipment requires excessive time to process the samples.

We are therefore investigating potential pre-treatment strategies to facilitate nail grinding without compromising the integrity of cortisol measurements. We have considered cryogenic or temperature-based treatments. I have been looking for papers on this, but so far without success.

If you are aware of any validated protocols, methodological papers, or relevant experience in this area, we would greatly appreciate your insights or references.