Care must be taken when using automatic coverslippers to ensure that

• A. The mounting medium applied is correct for long term storage
• B. The slide is perfectly clean
• C. The coverslip is of uniform thickness
• D. The temperature is within 5 C of room temperature

Answer: (A)

The key idea is choosing a mounting medium that is suitable for long-term storage. The mounting medium does more than just hold the coverslip in place; it protects the tissue, prevents dehydration, and provides a stable, refractive index–matched environment that remains clear and durable over time. If the medium isn’t appropriate for archival storage, long-term artifacts can develop—crystallization, yellowing, shrinking, or deterioration—that compromise slide integrity and diagnostic value.

While a clean slide helps avoid surface artifacts, a uniform coverslip thickness improves optics, and keeping the mounting medium at an appropriate temperature can aid proper curing, these factors do not address the slide’s longevity as directly as using a mounting medium formulated for long-term preservation.