Transmission Electron Microscopy Staining Methods for the Cortex of Human Hair: A Modified Osmium Method and Comparison with Other Stains

The study described a modified reduction-osmication method for staining human scalp hair, which improved reagent penetration through a cut fibre end, allowing better visualization of the cortex's ultrastructural features using transmission electron microscopy. This method was compared to other staining techniques, such as en bloc silver nitrate and section stains like uranyl acetate and lead citrate, phosphotungstic acid, potassium permanganate, and ammoniacal silver nitrate. The modified method aimed to address the poor penetration issue seen in traditional methods, enhancing the staining quality and reducing artefacts. The study also briefly examined the effects of hair-care treatments on staining outcomes.