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Cat. No.: PGMB-1 (for 1ml)

Cat. No.: PGMB-5 (for 5ml)

Description

Protein G Magnetic Beads, also known as Protein G immunomagnetic beads, Protein G immunoprecipitation magnetic beads, SPG magnetic beads, Protein G beads, Protein G immunomagnetic beads, or Protein G immunoprecipitation magnetic beads, are covalently coupled with high-quality recombinant Protein G and nano-sized amino magnetic beads. They can specifically bind to the corresponding antibodies and are primarily used for immunoprecipitation (IP), co-immunoprecipitation (Co-IP), or chromatin immunoprecipitation (ChIP). They can also be used for antibody purification from serum, cell culture supernatants, ascites, and other samples.

Protein G is an immunoglobulin-binding protein expressed by C-type or G-type streptococcal bacteria. Protein A is a cell wall surface protein found in Staphylococcus aureus with a molecular weight of 42 kDa. Protein G and Protein A have similar functions and can specifically bind to mammalian immunoglobulins (Ig), usually at the Fc region of the immunoglobulin. However, there is evidence showing that Protein A can also bind to the Fab region of the human VH3 family, and Protein G can sometimes bind to the Fab region as well. Additionally, they have different binding capacities for different subclasses of immunoglobulins. Recombinant Protein A and G, appropriately modified, are coupled to magnetic beads in a specific manner for use in immunoprecipitation and antibody purification.

Protein G magnetic beads are suitable for immunoprecipitation of human IgG1, IgG2, IgG3, IgG4; mouse IgG1, IgG2a, IgG2b, IgG3; rat IgG1, IgG2a, IgG2b, IgG2c; as well as rabbit and goat polyclonal antibodies. On the other hand, Protein A magnetic beads are suitable for immunoprecipitation of human IgG1, IgG2, IgG4; mouse IgG2a, IgG2b; and rabbit IgG, among others.

Recombinant Protein G in the product can specifically bind to the Fc region of most mammalian IgG antibodies, with a molecular weight of approximately 25 kDa. Through modification, the recombinant Protein G retains only the amino acid sequence relevant to binding the Fc region of IgG and eliminates sequences outside the binding site that may cause non-specific binding, effectively reducing non-specific binding. Each molecule of Protein G in this product can bind to three IgG molecules.

Protein G Magnetic Beads can specifically bind to the corresponding antibodies and can be conveniently used for immunoprecipitation or antibody purification of target proteins or protein complexes by utilizing magnetic separation devices such as magnetic racks. The table below summarizes the binding capabilities of our Protein A, Protein G, and Protein A/G Magnetic Beads products with common immunoglobulin subclasses in humans, mice, and rats, as well as their overall binding capabilities across different species.

• ++++, Strong Binding
• ++~+++, Medium Binding
• +, Weak Binding
• +/-, Weak or No Binding
• -, No Binding

The recombinant Protein G in this product can specifically bind to the Fc region of most mammalian IgG, with a molecular weight of approximately 25 kDa. This recombinant Protein G has been engineered to retain only the amino acid sequences related to IgG Fc binding, while removing sequences outside the binding sites that could cause nonspecific binding, effectively reducing nonspecific interactions. Each Protein G molecule in this product can bind to 3 IgG molecules.

Protein G Magnetic Beads can specifically bind to corresponding antibodies and, with the help of magnetic separation devices such as magnetic racks, can be conveniently used for immunoprecipitation (IP) of the target protein or its protein complex bound to the antibody, as well as for antibody purification experiments.

Features

• This product exhibits strong antibody binding specificity and high antibody binding capacity. Traditional Protein G agarose beads have a large pore size, making them prone to non-specific adsorption, while the magnetic beads in this product have a smaller particle size, reducing non-specific adsorption. Each milliliter of magnetic bead suspension contains approximately 10 mg of beads, with no less than 0.6 mg of recombinant Protein G. Each recombinant Protein G has three Fc-binding domains and can typically bind to no less than 0.7 mg of human IgG, with the specific maximum binding capacity depending on the antibody type and target protein. For a sample volume of 500 μL, typically only 10-20 μL of magnetic bead suspension is needed for efficient immunoprecipitation experiments.
• This product offers fast binding of antibodies or antibody complexes. The nanoscale magnetic beads (~200 nm) used in this product have a large surface area, facilitating rapid and effective binding with antibodies or antibody complexes. Usually, the adsorption process of antibodies or their complexes can be completed within 10 minutes, and the immunoprecipitation of the target protein can be accomplished within 30 minutes. Shortening the operation time helps to prevent degradation or denaturation of the target protein during prolonged procedures, ensuring the preservation of its activity. Magnetic separation allows for a 40% reduction in time compared to agarose beads when performing IP and Co-IP.
• This product offers multiple elution options. Depending on the structure, biological function, and subsequent application requirements of the target protein in the antibody complex, various elution methods can be employed, including acidic solutions, SDS-PAGE loading buffers, or competitive peptides for elution.
• This product is convenient to use. It is stored in a special protective solution without glycerol and can be rapidly and efficiently separated using magnetic adsorption, eliminating the need for centrifugation steps.

Precautions

• This product has been tested and can withstand repeated freezing and thawing for more than three cycles without affecting its performance.
• It is important to maintain the pH of the product between 6-8 and avoid high-speed centrifugation, drying, or freezing. Do not leave the magnetic beads in a magnetic field for an extended period as it may cause bead aggregation.
• Before using the product, it should be properly resuspended by gently inverting several times to ensure uniform mixing of the magnetic beads. Avoid vigorous vortexing or shaking, as it may lead to protein denaturation.
• During immunoprecipitation or purification, it is recommended to include positive and negative control groups.
• Protein samples should be purified as soon as possible after collection and kept at 4°C or on ice to slow down protein degradation or denaturation. To effectively inhibit protein degradation, an appropriate amount of protease inhibitor cocktail can be added to the protein sample.
• When using equipment such as a vacuum pump to aspirate the supernatant, be cautious of the suction strength to avoid aspirating aggregated magnetic beads.
• Aggregation of magnetic beads may occur during acid elution, which is a normal phenomenon and does not affect the normal use of the beads. The addition of 0.1% non-ionic detergent (such as Triton X-100, Tween-20, or NP-40) can effectively prevent bead aggregation without affecting the antibody binding efficiency of the magnetic beads.
• High concentrations of DTT, 2-mercaptoethanol, guanidine hydrochloride, and similar substances may have an impact on the binding of this product to labeled proteins.
• This product is intended for scientific research purposes by professionals only and should not be used for clinical diagnosis or treatment. It should not be used for food or drugs and should not be stored in a regular household.
• For your safety and health, please wear appropriate laboratory attire and disposable gloves when handling the product.

Storage

Store at 4°C, valid for two years. If not used for an extended period, it can be stored at -20°C, which allows for longer storage time.

Related:

• Protein A Magnetic Beads
• Protein A/G Magnetic Beads
• Protein G Magnetic Beads
• Protein G Plus Magnetic Beads
• Protein L Magnetic Beads

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

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