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Cat. No.: PLMB-1 (for 1 mL)

Cat. No.: PLMB-5 (for 5 mL)

Description

Protein L Magnetic Beads, also known as Protein L Immunomagnetic Beads, Protein L Immunoprecipitation Beads, Protein L Beads, or Protein L Immunoprecipitation Beads, are high-quality recombinant Protein L covalently coupled with nano-sized carboxyl magnetic beads. These beads can specifically bind to corresponding antibodies and are primarily used in immunoprecipitation (IP), co-immunoprecipitation (Co-IP), or chromatin immunoprecipitation (Ch-IP). They can also be used for the purification of antibodies from samples such as serum, cell culture supernatants, or ascites fluid.

The recombinant Protein L in this product can bind to the kappa light chains of most mammalian IgG, with a molecular weight of approximately 36 kDa. This recombinant Protein L has been selectively modified to remove the cell membrane binding domain and albumin binding domain, ensuring high specificity for binding IgG, making it a more versatile and convenient tool for the study and purification of immunoglobulins. Each Protein L molecule in this product has five IgG binding domains.

Protein L is an immunoglobulin light chain binding protein isolated from the cell wall of Peptostreptococcus magnus, with a molecular weight of 36 kDa. Protein A is a cell wall surface protein found in Staphylococcus aureus, with a molecular weight of 42 kDa, and Protein G is an immunoglobulin-binding protein expressed by Streptococcal bacteria. Protein L binds to antibodies through interaction with their light chains, with no involvement from any part of the heavy chain. Therefore, Protein L does not affect the antigen-binding sites of antibodies. This characteristic allows Protein L to bind a wider variety of antibodies from different sources and subclasses compared to Protein A and Protein G, including all types of IgG, single-chain variable fragments (ScFv), and Fab fragments. Despite its broader binding range, Protein L is not a universal antibody binding protein as it only binds to kappa light chains of antibodies.

Protein A and Protein G function similarly, specifically binding to mammalian immunoglobulins (Ig), typically at the Fc region of the immunoglobulins. However, some studies have shown that Protein A can also bind to the Fab region of the human VH3 family, and Protein G can occasionally bind to the Fab region as well. Both proteins vary in their binding affinities for different immunoglobulin subclasses. Appropriately recombinant-modified Protein A and G, coupled with magnetic beads, can be used for immunoprecipitation or antibody purification.

Protein L Magnetic Beads are suitable for purifying antibodies containing kappa light chains from mouse or human serum, cell culture supernatants, or ascites fluid. Protein L binds a wider variety of Ig types compared to Protein A and Protein G, including IgG, IgM, IgA, IgE, and IgD. Protein A Magnetic Beads are suitable for immunoprecipitating human IgG1, IgG2, IgG4, mouse IgG2a, IgG2b, and rabbit IgG, among others. Protein G Magnetic Beads are suitable for immunoprecipitating human IgG1, IgG2, IgG3, IgG4, mouse IgG1, IgG2a, IgG2b, IgG3, rat IgG1, IgG2a, IgG2b, IgG2c, and rabbit and goat polyclonal antibodies. 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

Protein L 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 has high antibody binding specificity and capacity: Traditional Protein L agarose gels have large pore sizes, which can lead to nonspecific adsorption, whereas this product’s magnetic beads are small in size, reducing nonspecific adsorption. Each milliliter of the magnetic bead suspension contains approximately 10 mg of beads, with no less than 0.6 mg of recombinant Protein L. Each recombinant Protein L has 5 kappa light chain binding domains and typically binds no less than 0.7 mg of human IgG, depending on the maximum binding capacity and the type of antibody and target protein. For each 500 µL sample, usually, only 10-20 µL of magnetic bead suspension is needed for efficient immunoprecipitation (IP) experiments.
• Fast binding speed with antibodies or antibody complexes: The nano-sized magnetic beads (~200 nm) used in this product have a large specific surface area, facilitating rapid and effective binding with antibodies or antibody complexes. Typically, the adsorption process for antibodies or their complexes can be completed within 10 minutes, and immunoprecipitation of the target protein can be completed within 30 minutes. Reducing the operation time effectively prevents degradation or denaturation of the target protein during extended operations, fully ensuring the activity of the target protein. Magnetic separation saves about 40% of the time for each IP and Co-IP compared to agarose gels.
• Multiple elution methods available: Depending on the structure, biological function, and subsequent application requirements of the target protein in the antibody complex, various elution methods can be used, including acidic solutions, SDS-PAGE sample buffer, or competitive peptides.
• Convenient to use: This product is stored in a special protective solution without glycerol, allowing for rapid and efficient separation via magnetic adsorption without the need for centrifugation.

Parameters

• Product Content: 10 mg/ml magnetic beads in specific protective buffer
• Beads Size: ~200 nm
• Magnetization: Superparamagnetic
• Coupled Protein: Recombinant Protein L
• M.W. of Protein: ~36 kDa (Protein L)
• Antibody Concentration: ≥ 0.6 mg Protein L per ml beads
• Binding Capacity: ≥ 0.7 mg human IgG per ml beads
• Specificity: Antibodies from various species, including mouse, human, and rat
• Elution Method: Elution with acid, competing peptide, or SDS-PAGE loading buffer
• Application: IP, Co-IP, Ch-IP, antibody purification

Storage

Store at 4ºC, valid for two years. For long-term storage, it can be stored at -20ºC, which will extend its shelf life further.

Precautions

• This product has been tested to withstand more than three freeze-thaw cycles without affecting its performance.
• Maintain the pH between 6-8; avoid high-speed centrifugation and drying. Do not leave the beads in a magnetic field for extended periods as it may cause aggregation.
• Properly resuspend the beads before use by gently inverting the tube several times to mix the beads thoroughly. Avoid vigorous vortexing to prevent protein denaturation.
• When performing immunoprecipitation or purification, it is recommended to set up both positive and negative control groups.
• Collect protein samples and complete the purification process as quickly as possible. Always keep the samples at 4ºC or on ice to reduce protein degradation or denaturation. Adding a suitable amount of protease inhibitor mixture to the samples can effectively inhibit protein degradation.
• If using a vacuum pump to aspirate the supernatant, be cautious of the suction strength to avoid drawing up the aggregated beads.
• Beads may aggregate during acidic elution, which is normal and does not affect their usability. Adding 0.1% non-ionic detergents (such as Triton X-100, Tween-20, or NP-40) can effectively prevent bead aggregation without affecting antibody binding efficiency.
• High concentrations of DTT, β-mercaptoethanol, and guanidine hydrochloride may affect the binding between the product and the tagged protein.
• This product is 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.
• For your safety and health, please wear a lab coat and disposable gloves while handling.

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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