If tissues have been fixed in an aqueous fixative, uric acid crystals can not be demonstrated.

• A. True
• B. False
• C. Not enough information
• D. Always

Answer: (A)

Uric acid crystals dissolve in water, so exposing tissue to a fixative that is aqueous will wash away or dissolve the crystals. Because the crystals are not preserved in water-based fixatives, they cannot be demonstrated after such fixation. To see uric acid crystals, you’d need non-aqueous fixation or fresh/frozen tissue where the crystals remain intact. That’s why the statement is true: aqueous fixatives hide or destroy these crystals, making them undetectable after fixation.