Thermo Scientific Pierce Protein L Magnetic Beads are high-capacity and high-throughput affinity particles for antibody purification using manual or robotic magnetic separators.
Recombinant Protein L, covalently attached to a blocked magnetic bead surface, selectively binds mouse and human antibodies through kappa light chains. The beads are commonly used to purify monoclonal antibodies in cell culture supernantants supplemented with bovine serum as Protein L does not bind bovine IgG. The Pierce Protein L Magnetic Beads can be used manually with a magnetic stand, as well as with automated platforms such as the Thermo Scientific KingFisher Instruments for high-throughput workflows.
- Selective – immobilized Protein L is ideal for selective purification of human and mouse antibodies that have kappa light chains
- Low non-specific binding – stable, pre-blocked beads provide clean purification of antibody
- Versatile – beads are compatible with manual and automated workflows (e.g., Thermo Scientific KingFisher Instruments)
- Purification of monoclonal and polyclonal antibodies that bind poorly to Protein A or Protein G magnetic beads
- Purification of monoclonal antibodies from culture supernatants supplemented with bovine serum
- Protein L IP and co-IP assays
- Purification of ScFv and Fab fragments containing kappa light chains
Thermo Scientific Pierce Protein L Magnetic Beads are typically used for purifying mouse and human antibodies containing kappa light chains from serum, cell culture supernatant or ascites. Protein L can bind a broader range of Ig classes than Protein A or Protein G, including IgG, IgM, IgA, IgE and IgD. Protein L binds strongly to human (kappa I, III and IV only), mouse (kappa I only), rat and pig immunoglobulins. It binds weakly to rabbit immunoglobulins and does not bind bovine, goat or sheep immunoglobulins. Single chain variable fragments (scFv) and Fab fragments also bind to Protein L. The protocol for the Pierce Protein L beads has been optimized to allow for high recovery and high purity of isolated antibodies.
Characteristics of Thermo Scientific Pierce Protein L Magnetic Beads.
||Recombinant Protein L monolayer covalently coupled to the surface of blocked magnetic beads
||Superparamagnetic (no magnetic memory)
||≥110μg of human IgG/mg of beads;
≥1.1mg human IgG/mL of beads
||Comparison of Protein L beads for mouse IgG purification. Thermo Scientific Pierce Protein L Magnetic Beads isolate more mouse IgG from cell culture supernatant than protein L magnetic beads from other suppliers. Using a KingFisher Flex Instrument with 96 deep-well plates, IgG was purified from cell culture supernatant using 50μL each of Pierce Protein L Magnetic Beads, and Protein L magnetic beads from BioVision (Supplier 1) and Bioclone (Supplier 2). The beads were incubated for 1 hour with undiluted cell culture supernatant containing 0.025% Tween-20, washed twice with in phosphate buffered saline containing 0.05% Tween-20 and once with water, and then eluted with 0.1M glycine, pH 2.0, for 10 minutes at room temperature. The eluates were resolved and stained with the Thermo Scientific Silver Stain Kit. Note that binding of mouse IgG with Protein L only occurs when kappa light chains are present. All of the beads tested were found to have negligible non-specific binding.
Review of antibody purification methods
Compare Protein A, Protein G and other antibody binding proteins
Affinities of Proteins A, G and L by species and antibody type (Tech Tip #34)
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