Helly, Zenker, and Orth solutions all contain mercury.

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

Answer: (B)

Mercury-containing fixatives have been used to preserve tissue, but not all fixatives in this list include mercury. Zenker’s solution contains mercuric chloride, and Helly’s solution is also commonly mercury-containing. Orth’s solution, in its standard formulations, does not use mercury and relies on other fixing agents. Because one of these fixatives is mercury-free, the statement that all three contain mercury isn’t accurate. Always verify the exact formulation for a given lot or brand, since recipes can vary.