MagnaLINK® 4FB Magnetic Beads (2.8 µm)


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SKU Unit Size Price
M-1004-010 1 mL

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MagnaLINK 2.8 µm 4FB Magnetic Beads provide a high surface area activated with the 4FB linker to enable easy covalent immobilization for user-defined, high-performance affinity purification schemes. They are colloidally stable with or without non-ionic detergents. The 4FB linker enables easy and efficient immobilization of any biomolecule modified with the complementary HyNic linker (Cat. No. S-1002-105) using ChromaLINK® technology. HyNic-modifed peptides, oligonucleotides, and antibodies rapidly form a stable conjugate bond with MagnaLINK 4FB Magnetic Beads. The MagnaLINK 4FB Magnetic Beads are validated and optimized for use with high-throughput magnetic platforms as well as for benchtop magnetic stands.


More Information
Bead Size 2.8 µm
Loading Capacity ≥ 25 nmol/mg
Reactivity HyNic
Applications Antibody Labeling, Aptamers, Next-Generation Sequencing (NGS), Photocrosslinking Studies
Recommended Storage 2° - 8°C – Do Not Freeze


Technical Information

Product Description

MagnaLINK 4FB magnetic microspheres are uniform, polymer encapsulated, nanometer-sized, super-paramagnetic particles activated with 4 formyl benzamide functionalities (4FB) see Figure 1. The aromatic aldehydes are introduced to the hydrophilic amino-modified surface by reaction with sulfo-succinymidly 4-formylbenzoate (Sulfo-S-4FB).

The high surface area and low non-specific binding of MagnaLINK 4FB magnetic microspheres are ideal for covalent immobilization of aromatic hydrazine-modified antibodies, peptides, DNA, RNA, oligonucleotides and/or oligosaccharides. The paramagnetic properties of these microspheres allow them to be used for the rapid separation of bound from unbound biomolecules using a suitably strong magnet.

Figure 1. MagnaLINK 4FB Magnetic Microspheres.


  • High surface area (2.8 ± 0.2 micron diameter)

  • Consistent aromatic aldehyde loading capacities (30-45 nmol/mg)

  • Encapsulated (no exposed iron) monodisperse microspheres

  • Fast magnetic response time (25 electromagnetic units)

  • 4FB is stable in aqueous solution for months at 4°C

  • Immobilizes approximately 120 ug IgG per mg of solid phase

  • Paramagnetic (no residual magnetism)

    % Solids: MagnaLINK 4FB magnetic microspheres are packaged at nominally 1% solids (10 mg/mL) as measured using spectroscopic analysis which is set by their optical density at 600 nm against a microsphere size standard.

    Aromatic Aldehyde (4FB) Functional Capacity: The aromatic aldehyde (4FB) surface capacity of each lot of particles is quantified by measuring the amount of unbound HyNic-peptide (OD280) left in solution versus an unmodified control microsphere after a 2 hour incubation. Refer to Certificate of Analysis for the specific 4FB functional capacity of each lot (nmol/mg).

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