Which preservation method is commonly used to preserve tissues for histology?

• A. Freeze
• B. Refrigerate
• C. Immerse in formalin
• D. Air dry

Answer: (C)

Preserving tissue structure for histology relies on fixation that stops enzymatic decay and locks cellular details in place. Immersing tissue in formalin is the standard approach because formalin creates cross-links between proteins, stabilizing both cells and surrounding matrix. This fixes morphology so the tissue can withstand the downstream processing steps—dehydration, clearing, and paraffin embedding—needed to cut thin, stainable sections for microscopic evaluation. Other methods aren’t as suitable for routine histology: freezing is mainly used for rapid cryosectioning but can introduce freezing artifacts and isn’t ideal for long-term preservation; refrigeration slows decay but doesn’t fix tissue; air drying damages structure and produces artifacts.