The primary stains for Verhoeff and aldehyde fuchsin are stable for months.

• A. True
• B. False
• C. Not specified
• D. Sometimes

Answer: (B)

Stain solutions for elastic fiber work are not meant to be long-life reagents. Verhoeff’s stain relies on a hematoxylin-based component that must be oxidized and combined with ferric chloride and iodine; over time, exposure to air, light, and varying pH causes changes in the dye chemistry, reducing staining intensity or altering color. Aldehyde fuchsin is also sensitive to oxidation and degradation; its ability to specifically highlight elastic fibers fades as the solution ages. For reliable results, these working solutions are prepared fresh or in small batches and used within a limited period, typically weeks or even days, and stored correctly (dark, cold conditions). Because they lose potency and consistency with time, they are not stable for months.