Which staining technique yields violet color for Nissl substance?

• A. Cresyl echt violet
• B. Luxol fast blue
• C. Masson's trichrome
• D. Verhoeff's Van Gieson

Answer: (A)

Nissl substance—clusters of rough endoplasmic reticulum and ribosomes in neurons—contains a lot of RNA, which is highly acidic. Basic dyes, such as cresyl echt violet, have an affinity for these acidic RNA-rich areas. When the tissue is stained with this dye, the RNA-rich Nissl bodies take up the stain and appear violet, making the neuronal cell bodies stand out clearly. Cresyl echt violet is specifically used for highlighting Nissl substance, so it yields the characteristic violet coloration you’re looking for.

The other stains are used for different tissue components: Luxol fast blue targets myelin, giving blue staining of white matter; Masson’s trichrome differentiates connective tissue components (like collagen) with multiple colors; Verhoeff’s Van Gieson is used to visualize elastic fibers and other connective tissue elements.