Which staining technique is demonstrated in the image?

• A. Aldehyde fuchsin
• B. Verhoeff stain
• C. Toluidine blue
• D. Masson's trichrome

Answer: (A)

Identifying elastic fibers by their color pattern. The image shows elastic fibers colored magenta, a hallmark of aldehyde fuchsin staining, which highlights elastin strongly in connective tissue such as vessel walls. Aldehyde fuchsin reacts with elastin to give that vivid pink-purple hue, making elastic fibers stand out from surrounding tissue.

If it were the Verhoeff stain, elastic fibers would appear black instead of magenta. Masson's trichrome would stain collagen blue (or green) and muscle red, not elastic fibers. Toluidine blue is a general stain that colors nuclei blue and can show metachromasia in certain tissues, but it does not selectively produce the magenta highlight of elastin seen with aldehyde fuchsin.

So the magenta staining pattern points to aldehyde fuchsin as the technique demonstrated.