The control slide for Masson's Trichrome uses tissue from which organ?

• A. Kidney
• B. Liver
• C. Cerebellum
• D. Aorta

Answer: (A)

Masson's Trichrome is designed to separate three tissue components by color: nuclei, cytoplasm, and collagen. A good control slide should clearly display all three color signals so you can verify that the stain is differentiating these elements properly and that the reagents are working.

Kidney tissue is ideal for this purpose because it provides a clear mix of features: the tubular epithelial cells have distinct cytoplasm that stains red, their nuclei stain dark, and the interstitium plus the capsule contain collagen fibers that stain blue. This combination gives a reliable, easily interpretable tri-color pattern that demonstrates successful separation of collagen from other tissue elements.

Other tissues listed don’t as reliably showcase all three color distinctions in a straightforward, consistent way: for example, some have less prominent collagen in a way that makes the blue stain harder to assess, or their architecture doesn’t emphasize the contrast between collagen and cytoplasm as clearly. That’s why kidney is used as the standard control for Masson's Trichrome.