“The more the better” is a good practice for applying mounting medium.

• A. True
• B. False
• C. It depends on the specimen
• D. It should be avoided completely

Answer: (B)

Mounting medium should be used in a thin, even film to properly cover and seal the tissue under the coverslip. Using more mounting medium than necessary does not improve the slide; it can cause problems. A excess amount can ooze out from under the coverslip, form beads or pools at the edges, create air bubbles, distort the tissue, and slow drying or curing. It can also alter the optical clarity if the excess medium changes the refractive index at the interface.

In practice, apply just enough mounting medium to wet the tissue surface and allow the coverslip to sit flat, producing a uniform seal without excess pooling. The amount isn’t about maximizing quantity; it’s about achieving a consistent, bubble-free, clear mount. While some variation in media viscosity or specimen thickness may require minor adjustments, the principle remains: more is not better. It should not be avoided completely, since mounting medium is needed to preserve and protect the slide.