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Cat. No.: TOSMB5-5 (for 5 mL)

Cat. No.: TOSMB5-50 (for 50 mL)

Cat. No.: TOSMB5-200 (for 200 mL)

Description

Tosyl Magnetic Beads (also known as Tosyl Beads, Tosylated Magnetic Beads, Tosyl Derivatized Beads, Toluenesulfonyl Derivatized Beads, or Tosylactivated Beads) are high-quality submicron-sized Fe₃O₄ microspheres coated with toluenesulfonyl (-Tosyl) groups. They are ready-to-use without the need for activation and can quickly, efficiently, sensitively, and specifically covalently conjugate with biomolecules such as peptides, proteins, antibodies, and oligonucleotides. These beads are essential tools in medical and life science research for applications such as immunoprecipitation (IP), cell sorting, and DNA-protein interactions.

Magnetic separation is a method that uses the force of an external magnetic field to combine and separate biomolecules and cells while preserving their biological activity. This method features high adsorption capacity, fast separation speed, high efficiency, reusability, and ease of operation. Conventional Fe₃O₄ microspheres, commonly used as magnetic materials, have high magnetic responsiveness and excellent biocompatibility, but their unmodified surfaces are unstable and prone to aggregation and precipitation.

Common functionalized magnetic beads include Tosyl Beads, NHS Beads, Carboxyl Beads, and Amino Beads. These beads have surface coatings of Tosyl, NHS, carboxyl, or amino functional groups to reduce aggregation and precipitation. Tosyl and NHS beads do not require activation and can be used directly. Carboxyl beads are acidic and usually activated with EDC/NHS in acidic buffers, while amino beads are alkaline and typically activated with glutaraldehyde in alkaline buffers.

This series of Tosyl Magnetic Beads are aqueous suspensions of superparamagnetic Fe₃O₄ microspheres coated with toluenesulfonyl groups. Advanced technology combines the magnetic beads with silica or polymer materials, creating a new type of functionalized magnetic microsphere. Compared to traditional magnetic beads, this series features superparamagnetism, high toluenesulfonyl density, fast magnetic responsiveness, monodispersity, rapid separation, high recovery rate, and strong specificity. They can easily and efficiently bind with various biomolecules (such as peptides, proteins, and antibodies) and serve as an excellent base material for coating, adsorption, chemical modification, and other subsequent treatments. Additionally, the silica/polymer shell of these Tosyl Magnetic Beads protects the target molecules bound to the beads from the negative effects of iron.

Principle of Covalent Conjugation with Biomolecules

The basic principle of covalent conjugation of Tosyl Magnetic Beads with biomolecules such as proteins and antibodies is as follows. Bioconjugation involves the chemical covalent bonding of biomolecules. Bioconjugation reagents contain reactive ends that can react with specific functional groups (such as primary amines or thiols). Primary amines (-NH₂) are present at the N-terminus of every peptide chain and in the side chains of lysine residues. Since primary amines are positively charged, they are usually found on the protein's outer surface, making them easier to conjugate without altering the protein's structure.

Tosyl Magnetic Beads do not require activation. Simply dissolve the biomolecule with primary amines or thiols in a coupling buffer, mix it with the Tosyl Magnetic Beads at 20-37ºC, and allow the reaction to proceed overnight or longer to covalently conjugate the biomolecule to the beads.

Features

• This series of Tosyl Magnetic Beads has high specificity, high ligand density, and high binding capacity. Compared to most similar products domestically and internationally, this series of Tosyl Magnetic Beads has a higher density of toluenesulfonyl groups, giving it strong reaction specificity with biomolecules containing primary amines or thiols. This series includes three particle sizes to choose from: 200 nm, 500 nm, and 1 µm. Each milliliter of magnetic bead suspension contains approximately 10 mg of beads, which can bind with no less than 0.6 mg of IgG antibodies, depending on the maximum binding capacity and the molecular weight of the biomolecules.
• Fast Reaction Speed with Biomolecules: This series of Tosyl Magnetic Beads has a high density of toluenesulfonyl groups, allowing them to quickly couple with biomolecules containing primary amines or thiols without the need for activation, saving operational time.
• Good Dispersion and Resuspension: This series of Tosyl Magnetic Beads is modified with silica or polymer materials, preventing bead aggregation. This ensures good monodispersity and stable physical and chemical properties, providing excellent reproducibility and convenience when conducting bioconjugation reactions with biomolecules.

Parameters

Storage

Store at 4ºC, valid for two years. Store at room temperature, valid for at least one week. Do not freeze at -20ºC or lower temperatures.

Precautions

• Freezing this product at -20ºC or lower will cause bead aggregation, affecting subsequent normal use.
• Choose appropriate functional groups and bead sizes based on the characteristics of the biomolecules.
• Maintain the pH of the Tosyl Magnetic Beads series between 6-8, avoid high-speed centrifugation and drying; do not keep the beads in a magnetic field for extended periods, as this may cause bead aggregation.
• Before using the Tosyl Magnetic Beads series, resuspend them adequately by inverting several times to mix the beads thoroughly and fully shaking or ultrasonically treating them to achieve a uniform suspension.
• To ensure optimal coupling efficiency, the coupling buffer should not contain Tris or other primary amine-containing solutions.
• Protein stabilizers (such as BSA, gelatin, etc.) will inhibit the binding of proteins/antibodies to Tosyl beads; therefore, ensure that the protein/antibody coupling system does not contain primary amine-containing protein stabilizers when coupling proteins/antibodies to Tosyl beads. The ligand sample solution should also not contain any proteins, sugars, or stabilizers, as these substances will react with Tosyl beads and affect the reaction between the ligand and the beads.
• If using a vacuum pump or similar instrument to aspirate the supernatant, pay attention to the suction strength to avoid drawing up aggregated beads.
• This product is intended for scientific research use by trained professionals only. It is not for clinical diagnosis or treatment, food, or drug use, and should not be stored in residential areas.

Related:

• Tosyl Magnetic Beads (200nm)
• Tosyl Magnetic Beads (500nm)
• Tosyl Magnetic Beads (1μm)

Only for research and not intended for treatment of humans or animals

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