What is the purpose of buffer solutions in pH calibration for staining procedures?

• A. Buffer solutions set known pH values used for calibration
• B. Buffer solutions provide nutrients for tissue
• C. Buffer solutions fix tissues
• D. Buffer solutions lubricate microscope lenses

Answer: (A)

Buffers provide reference pH values used to calibrate pH meters, which is essential because staining procedures rely on a specific pH to control how dyes interact with tissue components. By using buffers with known pH, you adjust the instrument so its readings reflect true pH, ensuring the staining solution stays at the intended acidity or basicity. This stability and accuracy lead to consistent dye uptake and color intensity across slides. Buffers help resist pH drift during staining, making results reproducible. They don’t nourish tissue, fix tissue, or lubricate lenses, which is why the other options don’t fit.