What is the fixative for Aldehyde fuchsin?

• A. 10% NBF
• B. Bouin
• C. Osmium tetroxide
• D. Zenkers

Answer: (A)

Aldehyde fuchsin is used to demonstrate elastic fibers, and the fixative chosen must preserve tissue structure without introducing pigments that interfere with the staining. Neutral buffered formalin (10%) provides stable crosslinking that preserves elastic fibers and maintains the integrity of the aldehyde fuchsin reaction. Bouin fixative contains picric acid and acetic acid, which can give a yellow background and alter staining quality, making it less suitable. Osmium tetroxide is a lipid- and membrane-focused fixative used mainly for electron microscopy, and it can change staining properties in ways that aren’t compatible with aldehyde fuchsin. Zenkers fixative is a strong crosslinker that can also affect color development. For reliable aldehyde fuchsin results, 10% neutral buffered formalin is the preferred fixative.