Phosphate Buffered Saline (PBS) is widely used in biological and biochemical research as a buffer solution to maintain a stable pH environment. It is commonly employed for washing cells during experiments, as it helps remove residual media or contaminants without causing osmotic stress. PBS is also utilized as a diluent for reagents and as a base for preparing solutions in immunoassays, such as ELISA. In cell culture, it serves as a rinsing agent before trypsinization to detach adherent cells. Additionally, PBS is used in immunohistochemistry to wash tissue sections and prevent nonspecific binding. Its isotonic nature makes it suitable for maintaining cell viability during procedures like flow cytometry. PBS is also integral in molecular biology techniques, including DNA and RNA extraction, where it aids in sample preparation and purification.