DEAE-DEXTRAN

Chemical and Biological properties

DEAE-Dextran offers a wide range of chemical and biological properties. The following properties are well documented:
① Adjuvant in vaccines
② Agent for transfection
③ Stabilizer of proteins
④ Agent for reduction of cholesterol count
⑤ Enhancer of viral infectivity

Uses

DEAE-Dextran is used in the development of sustained release protein delivery and nucleic acid transfection systems. The use of DEAE-Dextran as an efficient adjuvant in vaccine production is well established. For instance, DEAE-Dextran has been used for immunization of guinea pigs and swine with inactivated foot-and-mouth disease and rhesus monkeys with inactivated Venezulean equine encephalomyelitis virus, IVEE. The mechanism of action of DEAE-Dextran is not clear. The effect on the humoral response of rhesus monkeys to IVEE vaccine results in a typical IgM-IgG response. It has been speculated that DEAE-Dextran may cause a stimulation of the helper T-cell function in antibody synthesis.

Dextran derivatives

DEAE-Dextran, being a polycation, offers many applications, such as a component/adjuvant in vaccines, for transfection and gene therapy, cholesterol/weight modulation, a stabiliser of proteins, in drug delivery and as a flocculant.
DEAE-Dextran is made by reaction of dextran with (2-chloroethyl) diethylammoniumchlorid in alkaline solution.

DEAE - Dextran contains three basic groups with different pKa values. There are two tertiary groups, one in the single substituted glucose unit having a pKa value of approximately 9.2 and the tertiary group in the tandem substitution having a pKa value of approximately 5.5. The quaternary amino group in the tandem substitution has a pKa value ~ 14.
Like the polyanions, the polycations also exhibit a wide range of interesting biological properties. In particular, DEAE-dextrans appear to enhance a number of cellular processes. Many reports (398-401) testify to the enhancement of cellular uptake of viral RNA and also intact virus particles. Considerable interest has been focussed on the enhanced production of interferon by polyribonucleotide complexes in the presence of DEAE-dextran (402–404). These processes appear to operate without detrimental effects on the viability of the cells (398). To what extent these effects are due to the interaction between the cell surface (net negative charge) and the polycation is uncertain. For most of these studies, a DEAE-dextran with MW approx. 500 000 and DS 0.5 has been used at concentrations from 10–500 µg/ml.
DEAE-Dextran 500 is a polycationic derivative of dextran, produced from dextran with an average molecular weight >500,000 Da. DEAE-Dextran 500 has a broad variety of applications including medicinal products, technical and chromatographic applications and as a polycationic stabilizing molecule.
DEAE-Dextran 500 is supplied in its HCI form.

Uses

1. DEAE-Dextran 70 is a DEAE-derivative of dextran with an average molecular weight of 70000. It is supplied as white powder which is readily soluble in water.
2. DEAE-Dextran 500, a polycationic stabilizing molecule and transfection reagent, is used in the development of sustained release protein delivery and nucleic acid transfection systems. DEAE-Dextran 500 may be used for cell immobilization in biosensors.
3. DEAE-Dextran, being a polycation, offers many applications, such as a component/adjuvant in vaccines, for transfection and gene therapy, cholesterol/weight modulation, a stabiliser of proteins, in drug delivery and as a flocculant.
4. Used as a support for ion-exchange chromatography.
5. 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.
6. DEAE-Dextran is used for transfection in mammalian cell culture. The method is suitable for transient expression of cloned genes, but not for stable transformation of cells. Some cell types like BSC-1 cannot be exposed to calcium phosphate because of its toxicity. But DEAE-Dextran is as well toxic for cells and therefore this transfection method can only be used for certain cell types, e.g. CV-1 and COS cells. Another advantage of DEAE-Dextran transfection is the necessary lower DNA amount compared to calcium phosphate.

Chemical Properties

cationic bile acid sequestrant

Uses

Antidepressant

Uses

DEAE-Dextran is used in the development of sustained release protein delivery and nucleic acid transfection systems. It has been speculated that DEAE-Dextran may cause a stimulation of the helper T-cell function in antibody synthesis.