Low Density Aminoethyl Agarose (6% Cross-linked) – Catalog #B2025424

Low Density Aminoethyl Agarose (Catalog #B2025424) is a weak anion-exchange chromatography resin composed of 6% cross-linked agarose beads functionalized with a low density of primary amino groups. The primary amine functional groups are positively charged at neutral pH, allowing the resin to bind and resolve negatively charged proteins. The "low density" designation indicates a reduced substitution level, which minimizes nonspecific interactions and is useful for applications where selectivity is more important than binding capacity.

Scientific Overview

Ion exchange chromatography separates proteins based on their surface charge. Anion-exchange resins bind negatively charged molecules while allowing neutral or positively charged proteins to flow through. The primary amino group (pKa ~9) carries a positive charge above pH 5, making aminoethyl-functionalized agarose a weak anion exchanger useful across a wide pH range. Low-density resins reduce nonspecific hydrophobic interactions and are often preferred when separation resolution is more critical than maximum binding capacity—for instance, when purifying similar proteins or performing polishing steps after earlier chromatography.

Key applications include:

• Anion-exchange chromatography and protein fractionation
• Buffer exchange and desalting of protein solutions
• Polishing and intermediate purification steps
• Selective separation of acidic proteins and nucleic acids
• Gentle separation conditions to preserve protein integrity

Usage & Handling Guidance

Store the suspension at 2–8°C. Before use, gently resuspend and allow the resin to settle to assess the bed height. Pack the column according to standard practice (gravity flow or pump) and equilibrate thoroughly with the starting buffer. Optimize pH and salt concentration empirically for your protein pair; typical working pH is 7–9.

• Buffer pH: Effective from pH 5 to >9; the effective range depends on the pKa of your protein and the resin charge.
• Ionic strength: Begin with low salt (e.g., 20 mM Tris, pH 8.0) and increase salt in a gradient to elute bound protein.
• Loading: Start conservatively; the low density limits maximum capacity, so optimize for selectivity.
• Regeneration: Wash with high-salt buffer (e.g., 1 M NaCl) to strip protein, then re-equilibrate before the next run.

What You Get

• 25 mL of low-density aminoethyl agarose suspension (6% cross-linked)
• Weak anion-exchange resin suitable for selectivity-focused applications
• Enough material for multiple purification experiments
• For research use only (RUO)

Why Researchers Choose It

• Low charge density for higher selectivity and lower nonspecific adsorption
• Gentle conditions suitable for sensitive proteins and regulatory molecules
• Wide effective pH range (pH 5–>9)
• Cost-effective for development and polishing steps

Frequently Asked Questions (FAQ)

• What is the difference between low density and standard density aminoethyl agarose?
  Low-density resin has fewer amino groups per unit volume, reducing nonspecific binding and improving selectivity, though with lower maximum binding capacity.
• What pH range should I use?
  Aminoethyl is a weak anion exchanger with a pKa around 9. Effective separation typically occurs from pH 5 to >9, but optimize based on your protein's isoelectric point.
• Can I use this for cation exchange?
  No. This resin is positively charged and binds negatively charged molecules. For cation exchange, use carboxymethyl (CM) or sulfopropyl (SP) resins.
• How do I pack a column with this resin?
  Follow standard chromatography packing procedures: allow the resin to fully suspend, pour into a column, and flow buffer through slowly until the bed height is stable.
• Can I get a COA or technical datasheet?
  Request a quote or contact us and we will provide available lot documentation.

References

• López-Gallego F, Montes T, Fuentes M, Alonso N, Grazu V, Betancor L, Guisán JM, Fernández-Lafuente R. Improved stabilization of chemically aminated enzymes via multipoint covalent attachment on glyoxyl supports. J Biotechnol. 2005;116(1):1-10.
• Knödler M, Rühl C, Opdensteinen P, Buyel JF. Activated Cross-linked Agarose for the Rapid Development of Affinity Chromatography Resins - Antibody Capture as a Case Study. J Vis Exp. 2019;(150).
• Wilchek M, Miron T. Limitations of N-hydroxysuccinimide esters in affinity chromatography and protein immobilization. Biochemistry. 1987;26(8):2155-61.