Potassium dichromate fixative dissolves DNA while preserving lipids and mitochondria. Which statement describes its action?

• A. Dissolves DNA; preserves lipids and mitochondria
• B. Cross-links proteins to preserve nucleoproteins
• C. Dehydrates tissue rapidly
• D. Stains iron-containing compounds

Answer: (A)

Potassium dichromate fixative works by oxidizing and breaking down nucleic acids, so DNA is dissolved, while lipid-containing structures and mitochondria stay intact enough to be preserved. This creates a distinct preservation pattern: nucleic acids are degraded, but membranes and mitochondria remain visible for subsequent processing and staining. This differs from fixatives that mainly cross-link proteins to protect nucleoproteins, or from dehydrating agents that remove water aggressively, or from stains that target iron-containing compounds rather than fixatives.