Thermo Scientific™ Polyethyleneimine (PEI), M.W. 50,000–100,000, supplied as a 30% (w/w) aqueous solution, is a high–molecular-weight, branched, highly cationic polymer used across biotechnology, nanotechnology, industrial chemistry, environmental treatment, coatings, and materials science. The branched structure contains a rich mixture of primary, secondary, and tertiary amine groups, enabling high charge density and strong binding capacity.

This PEI grade is widely used as a protein precipitant, making it valuable in biochemical purification workflows. Its strong electrostatic interactions enable efficient binding and flocculation of proteins, nucleic acids, and anionic contaminants. Beyond biotechnology, its robust polymeric structure and high molecular weight make it ideal for chelating metals, scavenging aldehydes/oxides, stabilizing colloids, modifying surfaces, and enhancing industrial formulations.

Supplied as a colourless to pale yellow, odourless, viscous liquid, it dissolves easily in water and remains stable at ambient storage conditions.

Key Features & Benefits

High-Molecular-Weight (50,000–100,000) Branched PEI

• Stronger flocculation and precipitation performance than lower-MW PEIs
• Forms durable polyelectrolyte complexes
• Ideal for thick, robust coatings and high-strength hydrogel structures

30% (w/w) Aqueous Solution

• Ready-to-use format—no melting or reconstitution required
• Lower viscosity than solid PEI powders of similar molecular weight
• Easily diluted in water and buffering systems

Highly Functional Branched Cationic Polymer

• Excellent protein precipitant for biochemical purification
• Strong chelator for heavy metals and metal oxides
• Efficient scavenger for aldehydes in chemical processes
• Assists in dewatering, clarification, and water treatment systems

Industrial Versatility

Used extensively in:

• Detergents and cleaning formulations
• Paper and pulp processing (wet strength improvement, retention aid)
• Dye and pigment processing
• Printing inks and specialty coatings
• Wastewater and effluent treatment
• Nanoparticle stabilisation and surface modification

Chemical & Regulatory Information

Physical & Analytical Characteristics

Applications

1. Biotechnology & Protein Chemistry

• Protein precipitation for purification
• Removal of nucleic acids and anionic contaminants
• Clarification of cell lysates & fermentation broths

2. Water & Environmental Treatment

• Strong cationic flocculant
• Chelator for heavy metals
• Scavenger for aldehydes and oxide species
• Industrial wastewater clarification

3. Industrial Manufacturing

• Additive in detergents and cleaning formulations
• Paper industry retention & wet-strength agent
• Dye and pigment processing
• Printing inks and specialty coatings

4. Polymer & Material Science

• Nanoparticle coating & stabilization
• Component of polyelectrolyte multilayers
• Hydrogel formation & biomaterial development
• Crosslinker and adhesion enhancer in resins

Ordering Information

Thermo Scientific™ Polyethyleneimine (PEI), M.W. 50,000–100,000 (30% w/w aqueous solution), is a high–performance, branched cationic polymer widely used for protein purification, water treatment, chemical processing, industrial formulation, and nanomaterials engineering. With its strong cationic charge, high molecular weight, and ready-to-use aqueous format, it is an indispensable reagent for both research and industrial production environments.