Picric acid fixation is associated with which effect on tissue?

• A. Hydrolyze nuclei
• B. Causes shrinkage
• C. Preserves glycogen
• D. Increases mitotic index

Answer: (B)

Picric acid fixation causes tissue shrinkage because picric acid is a strong dehydrating agent. In fixatives like Bouin’s solution, which contains picric acid, water is pulled out of the tissue rapidly, and the tissue contracts as proteins and extracellular components lose water. This leads to noticeable shrinkage artifacts, especially in delicate specimens. The other effects listed don’t describe what picric acid fixation does: it does not hydrolyze nuclei, it does not reliably preserve glycogen, and fixation does not increase the mitotic index.