SP-Sephadex is widely used in protein purification processes, particularly in ion exchange chromatography. It is especially effective for the separation and purification of positively charged biomolecules such as proteins, peptides, and nucleic acids under low ionic strength conditions. Due to its strong cation-exchange properties provided by sulfopropyl groups on a cross-linked dextran matrix, it binds target molecules at neutral to slightly acidic pH, allowing impurities to be washed away before eluting the purified substance with an increasing salt gradient. It is commonly used in both laboratory-scale research and industrial bioprocessing for downstream purification of therapeutic proteins, antibodies, and enzymes. Its high capacity, chemical stability, and compatibility with standard chromatography systems make it a preferred choice in biotechnology and pharmaceutical applications.