The sections for the stain shown in the image must be prepared as which method?

• A. Frozen and cut at 20-30 micrometers
• B. Paraffin and cut at 5-10 micrometers
• C. Frozen and cut at 1-5 micrometers
• D. Paraffin and cut at 50-60 micrometers

Answer: (A)

When a stain requires preservation of components that are altered or removed by paraffin processing, freezing the tissue is the better choice. Freezing avoids solvent extraction and dehydration, helping the stain reveal true features that would be distorted in paraffin sections. Cutting thicker cryosections, around 20–30 μm, gives enough depth for the stain to penetrate and for the tissue to stay intact under light microscopy, while still providing clear morphology. Parffin sections are usually much thinner (5–10 μm) and would not preserve the target as reliably for this stain, and ultra-thin or very thick sections would compromise visibility and handling. So, freezing and cutting at 20–30 μm best aligns with preserving the needed tissue characteristics for this stain.