Phosphate buffer solution (pH 7.2) used to maintain a stable pH in biological and chemical experiments. Commonly applied in cell culture, protein purification, and enzyme reactions where pH control is critical. Frequently used in pharmaceuticals for drug formulation to ensure compatibility with physiological pH. Also used in diagnostic kits and analytical chemistry for calibration and sample preparation. Suitable for use in molecular biology techniques such as PCR, electrophoresis, and chromatography due to its non-reactive nature.