Thermo Scientific Pierce Protein G Magnetic Beads are high-capacity and high-throughput affinity particles for antibody purification and immunoprecipitation methods using manual or robotic magnetic separators.
Recombinant protein G, covalently attached to a blocked magnetic bead surface, can bind to antibodies from many different species, enabling purification of antibodies from crude extracts. Immunoprecipitation assays performed with protein G coated beads result in high yield of target antigen with very low background. Using our crosslinker chemistry, you can immobilize an antibody onto the magnetic particle and prevent IgG contamination in IP or Co-IP experiments. The Pierce Protein G Magnetic Beads can be used both manually with a magnetic stand as well as with automated platforms such as the Thermo Scientific KingFisher Instruments for high-throughput workflows.
- High efficiency – equivalent or higher yield of IP target antigens than magnetic beads from other suppliers
- Low non-specific binding – stable, pre-blocked beads provide highly purified product (e.g., antigen eluted in IP with antibody is devoid of contaminating protein from complex cell lysate)
- Consistent – magnetic beads eliminate resin loss and provide for more efficient separation of solutions than traditional IP methods that use only centrifugation
- Versatile – beads are compatible with manual and automated workflows (e.g., Thermo Scientific KingFisher Instruments)
- IP and Co-IP experiments
- Antibody purification
Thermo Scientific Pierce Protein G Magnetic Beads are used for purifying antibody from serum, cell culture supernatant or ascites as well as for IP/Co-IP of antigens from cell or tissue extracts. Protein G can bind to antibodies from many different species, including mouse, human, rabbit, cow, goat and sheep. The protocol for the Pierce Protein G beads has been optimized to allow for high recovery and high purity of the isolated antibody or antigen. Antibody or antigen/antibody complex (IP) is first captured on the magnetic beads. The beads are washed and then the target is eluted with low pH elution buffer. IP performance is equivalent to or better than Protein G magnetic beads from other suppliers.
Characteristics of Thermo Scientific Pierce Protein G Magnetic Beads.
||Recombinant Protein G monolayer covalently coupled to the surface of blocked magnetic beads
||Superparamagnetic (no magnetic memory)
||≥60μg of rabbit IgG/mg of beads;
≥600μg rabbit IgG/mL of beads
|Comparison of binding capacities for human and rabbit IgG. Thermo Scientific Pierce Protein G Magnetic Beads have approximately three times the IgG binding capacity of Dynabeads™ G (Life Technologies). Beads were added to a 96 deep-well plate (100μL beads per well). Using the Thermo Scientific KingFisher Flex Instrument, the beads were incubated for 1 hour with 400μg purified human or rabbit IgG. Binding was calculated using the Thermo Scientific BCA Protein Assay by subtracting the amount of IgG in the flow-throughs from the IgG loaded onto the beads.
|Better immunoprecipitation results with Thermo Scientific Pierce Protein G Magnetic Beads. EGF Receptor antibody (5μg) was incubated overnight at 4°C with 0.75mg of A431 cell lysate. Using the KingFisher Flex Instrument, 25μL each of Pierce Protein G Magnetic Beads, Dynabeads™ G (Life Technologies, Supplier 1), Protein G Magnetic Sepharose™ (GE Life Sciences, Supplier 2) and PureProteome™ Protein G beads (Millipore, Supplier 3) were added to 96 deep-well plates. The beads were incubated for 1 hour with the antigen/antibody complex at room temperature, washed twice in phosphate buffered saline containing 0.05% Tween™ 20, washed once in water and then eluted in 0.1M glycine, pH 2.0. Samples were resolved by SDS-PAGE and analyzed by Western blot for EGFR. The Pierce beads were found to have higher yield of EGFR than other Protein G beads tested. An accompanying silver-stained gel (not shown) confirmed that non-specific binding was negligible for all beads tested.
Review of antibody purification methods
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