Which stain is commonly used to visualize collagen fibers in connective tissue?

• A. Masson Trichrome
• B. Verhoeff
• C. Gomori
• D. H&E

Answer: (A)

Visualizing collagen fibers clearly relies on a stain that differentiates collagen from other tissue elements, providing a strong color contrast. Masson Trichrome is designed for this purpose: collagen fibers color blue (or green, depending on the protocol), while muscle and cytoplasm stain red and nuclei appear dark. This distinct contrast makes collagen networks easy to identify and assess for fibrosis or structural organization.

Verhoeff stains elastic fibers, not collagen, so it highlights elastin rather than the collagen framework. Gomori’s stain variants are often used for reticular fibers or basement membranes, not the general collagen network. H&E is a routine stain that colors collagen faintly and similarly to surrounding tissue, offering less specific visualization of collagen fibers.