A Novel Application of a Cryosectioning Technique to Aid Scat Hair Microanalysis

Scat hair presents a diverse profile of hairs for morphological assessment that may find versatile applications in wildlife forensic investigations. Successful morphological assessment of scat hair microstructure, however, depends on a robust sectioning methodology. We assessed the feasibility and efficacy of a cryosectioning technique compared to that of a gold standard hand-sectioning technique. Scat hairs were embedded in paraffin wax and hand-sectioned, while cryopreserved scat hairs were sectioned with a cryostat. The results showed that cryosectioning preserved the pristine morphology of the scat hair and provided cross sections more amenable to high-resolution imaging of hair internal microstructure than hand-sectioning. The cryosectioning technique may find novel applications as a more reliable and robust technique to aid (i) scat hair internal microstructure analysis for cross-referencing with species identification keys in wildlife forensic studies and (ii) downstream toxicological analysis in wildlife forensic studies as hair biochemistry is not altered during cryopreservation.