Unlocking the Versatility of DEAE-Dextran 500 in Modern Biopharma
From gene transfection and vaccine adjuvants to protein stabilisation and advanced drug delivery, DEAE-Dextran 500 offers broad functionality backed by cationic strength, pH versatility, and proven GMP-quality.
DEAE-Dextran (diethylaminoethyl dextran) is a polycationic derivative of dextran with broad utility in pharmaceutical and biomedical applications. It is commonly used as a component or adjuvant in vaccines, a transfection agent in gene therapy, a stabiliser for proteins, and as a carrier in drug delivery systems.
What is DEAE-Dextran?
DEAE-Dextran is synthesised by reacting dextran with (2-chloroethyl) diethylammonium chloride in an alkaline solution. The result is a polycationic polymer containing both tertiary and quaternary amine groups. These functional groups give DEAE-Dextran its cationic charge, which is critical for its biological activity—especially in electrostatic interactions with nucleic acids, proteins, and cell surfaces.
The Chemistry Behind DEAE-Dextran’s Cationic Power
It contains three types of basic groups with distinct pKa values:
Tertiary amine in single substitution: pKa ~9.2
Tertiary amine in tandem substitution: pKa ~5.5
Quaternary nitrogen group: Permanently charged; no true pKa
This complex charge profile contributes to its utility in pH-sensitive drug delivery systems and enhances its versatility in formulation.
Titration Profile of DEAE-Dextran
The titration curve of DEAE-Dextran following alkylation reveals key insights into its chemical structure:
The grey bar indicates the point at which excess sodium hydroxide is titrated.
The light blue bar corresponds to the titration of the tertiary amine group (pKa ~9.2).
The dark blue bar indicates titration of the tandem substitution group (pKa ~5.5).
These peaks reflect the protonation behaviour of the amine groups and are used to confirm substitution efficiency and functionality.
The total nitrogen content—approximately 3.2%—can be determined by titration or Kjeldahl analysis, equating to one charged group per three glucose units. Analysis also reveals that DEAE-Dextran contains a higher proportion of tertiary amine groups than quaternary amines, with about two-thirds of the nitrogen originating from tandem substitutions.
Stability Profile
DEAE-Dextran 500 demonstrates excellent stability:
In solution, it remains stable at ambient temperatures across a broad pH range (4–14).
As a dry powder, it maintains long-term stability under normal storage conditions.
This stability makes DEAE-Dextran suitable for a wide range of formulations, including those requiring autoclaving, lyophilisation, or pH adjustments.
Pharmacosmos' DEAE-Dextran 500
Pharmacosmos' DEAE-Dextran 500 is based on our world-renowned dextran backbone and is manufactured at our state-of-the-art, GMP-certified facility in Denmark. In line with Pharmacosmos’ long-standing commitment to quality, this product is developed and produced to the same high standards applied across our pharmaceutical-grade dextran portfolio.
Pharmacosmos DEAE-Dextran 500 Pharmaceutical Quality offers:
Proven cationic functionality and defined substitution profile
High purity and GMP-compliant manufacturing
Excellent solubility and long-term stability
Versatility in gene therapy, protein stabilisation, and drug delivery
Frequently Asked Questions (FAQ)
What is the typical nitrogen content of DEAE-Dextran 500?
The nitrogen content is approximately 3.2%, which corresponds to one charged group per three glucose units.
Is DEAE-Dextran stable in solution?
Yes, DEAE-Dextran is stable in solution at ambient temperatures and across a wide pH range (4–14).
What are the main applications of DEAE-Dextran?
It is commonly used in gene transfection, as a vaccine adjuvant, in protein stabilisation, and in drug delivery systems.
Can DEAE-Dextran be autoclaved?
Yes, it can withstand sterilisation processes such as autoclaving, making it suitable for use in aseptic formulations.
How is DEAE-Dextran characterised?
It is typically characterised via titration curves, nitrogen analysis (e.g., Kjeldahl), and substitution efficiency assessments.
PhD, Medicinal Chemistry, University of Copenhagen
MSc, Applied Chemistry and Chemical Engineering, DTU - Technical University of Denmark
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