DEAE-dextran, MW 500000 hydrochloride (DEAE-dextran, MW 500000 hydrochloride, from bacterial [Leuconostoc mesenteroides]) is a high molecular weight, positively charged polymer that notably enhances the uptake of viral RNA by cultured cells. It is employed in "tumor immunity" RNA-spleen cell transfer systems, significantly prolonging the lifespan of tumor-bearing animals, comparable to those with active immunity. DEAE-dextran acts as a nucleic acid complexing agent, forming composite particles with DNA/RNA, and is widely used in gene delivery. Additionally, it serves as a coating for liposomes.