Effect of Hydrogen Peroxide and Potassium Hydroxide Softening Treatments on the Histological Preparation and Morphology of Sunda Porcupine (Hystrix javanica) Quills.

The Sunda porcupine (Hystrix javanica) possesses keratin-based quills with exceptional rigidity, necessitating softening porcupine treatments for histological and ultrastructural analyses. This study evaluated the effectiveness of 30% hydrogen peroxide (H2O2) alone and in combination with 20% potassium hydroxide (KOH) on true, flat and rattle quills. Quills from 12 captive Sunda porcupines were subjected to treatments of varying durations and examined using histology and scanning electron microscopy (SEM). Treatment with 30% H2O2 produced moderate softening after 3 days in flat and rattle quills, whereas true quills required 7 days of immersion but remained less effectively softened. In contrast, the combined treatment of 30% H2O2 and 20% KOH achieved effective softening within 25-30 min, resulting in softer texture, increased quill diameter and improved sectioning quality. Histological analyses revealed structural differences among quill types, while SEM showed that 30% H2O2 alone produced surface cracking while retaining discernible interfibrillar boundaries. In contrast, the combined treatment with 30% H2O2 and 20% KOH resulted in a more irregular macrofibril surface, indistinct interfibrillar boundaries and interfibrillar fusion. These findings indicate that the H2O2 + KOH protocol provides a more efficient and rapid method than H2O2 alone, although optimization is necessary to minimise artefacts and preserve structural integrity. Overall, this combination offers a practical approach for preparing porcupine quills for microscopic evaluation, while future studies should investigate milder alternatives and explore the biomedical potential of quill-derived keratin.