A good fixative should penetrate slowly.

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

Answer: (B)

Fixation aims to stop cellular processes and lock structures in place throughout the tissue, which requires the fixative to move through all parts of the specimen efficiently. If penetration happens slowly, the outer regions fix first while the inner areas remain unfixed longer, allowing autolysis and enzymatic changes to continue. That leads to artifacts, uneven fixation, and unreliable staining. So, a good fixative should penetrate quickly to achieve uniform preservation across the tissue. In practice, tissue size, fixative viscosity, and temperature affect penetration, so techniques like cutting smaller pieces or using fixatives with better diffusion help ensure rapid, even fixation. The statement is not correct because speed of penetration is important for quality fixation; the other options aren’t needed when you understand this principle.