Question

Safranin stains

• A. Lignified walls green.
• B. Lignified walls blue.
• C. Lignified walls and nuclei red.
• D. Lignified walls and nuclei yellow.

Answer 1

Answer: (C)

Lignified walls and nuclei red.

Safranin O is a basic dye that will stain red any acidic features of the tissue, e.g., nuclei and lignified secondary cell walls that surround mature xylem cells in vascular bundles, while fast green is an acidic dye that will stain green the basic components of tissue, such as cytoplasm and cellulosic primary (growing) cell walls. This combination of dyes allowed us to highlight lignified tissue in xylem vessel walls (red) and cellulosic phloem cell walls (green).

Hence the correct answer is (C).