During decalcification, to what thickness should specimens be cut for adequate penetration?

• A. 3-4 mm
• B. 1-2 cm
• C. 0.5 mm
• D. 5-6 mm

Answer: (A)

The ability of a decalcifying solution to work depends on diffusion into the tissue. The chemical needs to reach the inner parts of the specimen to remove calcium salts evenly, and diffusion is much slower with thicker pieces. Cutting specimens to about three to four millimeters thick creates enough surface area for the solution to penetrate quickly and reach the center, providing uniform decalcification without leaving an undecalcified core. This thickness balances getting the job done in a reasonable time while preserving tissue morphology for subsequent processing, embedding, and staining. If the piece is thicker, inner regions may remain calcified and hard, leading to incomplete decalcification and problems during sectioning and staining.