Which fixative preserves water-soluble tissue components such as urate crystals in gout and glycogen, preserves pigments, dissolves fat, and can overhardens tissue?

• A. Acetone
• B. Methyl Alcohol
• C. Ethyl Alcohol
• D. Carnoy's Solution

Answer: (C)

Ethyl alcohol fixes tissue mainly by precipitating proteins and removing water, which makes it excellent at preserving water-soluble components like glycogen and urate crystals that would be leached out by aqueous fixatives. It also helps maintain pigments by avoiding oxidative changes associated with watery fixatives. At the same time, alcohol acts as a lipid solvent, so fats are dissolved during fixation. The dehydration effect can be strong, so overexposure can overhardenen tissue. Taken together, these properties describe an alcohol-based fixative that preserves water-soluble structures and pigments while dissolving fat and potentially making tissue very hard if used too aggressively.