Used in biochemical and molecular biology experiments to maintain a stable acidic pH, typically in the range of 1.5 to 3.5. Commonly applied in protein purification, enzyme activity assays, and studies involving acid-stable proteins or enzymes such as pepsin. Also used in chromatography and electrophoresis under acidic conditions. Its low ionic strength and minimal interference with protein structure make it suitable for functional and structural studies of biomolecules in acidic environments.