Diethylaminoethyl (DEAE)-dextran is a polycationic derivative of the carbohydrate polymer dextran, and it is one of the first chemical reagents used to transfer nucleic acids into cultured mammalian cells (Vaheri and Pagano, 1965). The cationic DEAE‑dextran molecule tightly associates with the negatively charged backbone of the nucleic acid, and the net positive charge of the resulting nucleic acid-DEAE‑dextran complex allows it to adhere to the cell membrane and enter into the cytoplasm via endocytosis or osmotic shock induced by DMSO or glycerol.

The advantages of DEAE-dextran method are its relative simplicity, reproducibility, and low cost, while its disadvantages include cytotoxicity and low transfection efficiency for a range of cell types (typically less than 10% in primary cells), as well as the requirement for reduced serum media during the transfection procedure. In addition, this method is limited to transient transfections, and is not suitable for generating stable cell lines.

Mix nucleic acid with DEAE-dextran solution in transfection medium or phosphate-buffered saline solution. Nucleic acid-DEAE-dextran complexes are formed via electrostatic interactions between the polymer and phosphate backbone of the nucleic acid.

Add the nucleic acid-DEAE-dextran complexes to the cells, which adhere to the cell surface via electrostactic interactions.

Induce the uptake of the nucleic acid-DEAE-dextran complexes by osmotic shock using DMSO or glycerol.

Wash cells to remove the complexes and incubate to allow gene expression.

Assay cells for transient gene expression.

DEAE-dextran-mediated transfection workflow.