PBS, or phosphate-buffered saline, is widely used in biological and biochemical research due to its ability to maintain a stable pH environment similar to that of human body fluids. It is commonly employed in cell culture techniques for rinsing cells and tissues without causing damage or osmotic stress. PBS is essential in immunoassays such as ELISA and immunohistochemistry, where it serves as a diluent and wash buffer to reduce non-specific binding. It is also used in protein purification, flow cytometry, and microscopy to maintain physiological conditions during sample preparation. Due to its non-toxic nature and compatibility with living cells, PBS is a standard solution in laboratory procedures involving cells, antibodies, and diagnostic applications.