Used in molecular biology and biochemistry to enhance the uptake of nucleic acids into cells during transfection. It is commonly applied in vitro to facilitate the introduction of DNA or RNA into cultured cells, especially in cell lines that are difficult to transfect. DEAE-Dextran works by binding nucleic acids and promoting their attachment to the cell membrane, increasing internalization through endocytosis. It is also used in protein purification and separation techniques due to its ion-exchange properties. Additionally, it serves as a carrier for antigens in immunological studies, enhancing immune response.