Which constituents are found in Zenker fixative?

• A. Acetic acid, picric acid, potassium dichromate
• B. Formaldehyde and potassium dichromate
• C. Paraformaldehyde and sodium phosphate di-
• D. Acetic acid and formaldehyde

Answer: (A)

Zenker fixative preserves tissue by using an acidic, oxidizing environment to stabilize cellular components and proteins, giving sharp nuclear detail and good overall morphology. The key ingredients that define this fixative are acetic acid, which aids rapid penetration and preserves nuclear detail; potassium dichromate, which acts as an oxidizing fixative to cross-link proteins and stabilize structures; and, in many standard formulations, a component like picric acid is included to enhance tissue preservation and staining characteristics. This combination—acetic acid with a chromium-based oxidizer and the added stabilizing effect of picric acid—fits Zenker fixative’s traditional makeup. The other options describe fixatives built on aldehydes or omit essential components, so they don’t match Zenker’s formulation.