Phosphate buffer solution with pH 7.8-8.0, 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. Ideal for diluting substances in immunoassays and used in diagnostic tests, including ELISA and immunohistochemistry. Frequently employed in pharmaceutical formulations to ensure drug stability. Also used in sample preparation for HPLC and other analytical techniques. Suitable for rinsing membranes and tissues in laboratory procedures.