TECHNO CHEMICAL corp.

When circumstances call for the rapid development of microsphere reagents, particles coated with affinity binding proteins offer a ready solution. Affinity binding protocols are straightforward, typically involving a simple incubation of the spheres with the appropriate ligand. Binding proteins also provide an opportunity to optimally orient the ligand, as with the end-point immobilization of biotinylated oligonucleotides to streptavidin-coated microspheres, or the Fc-specific immobilization of antibodies via Protein A or G. Particles coated with binding proteins also find significant use in purifications. Streptavidin-coated microspheres are often used in the isolation of biotinylated PCR amplicons. Protein A and Protein G microspheres are utilized for purification of antibodies and Fc-tagged fusion proteins, as well as for the recovery of Ab/Ag complexes in immunoprecipitation. Protein A and Protein G are proteins that readily bind the Fc regions of many types of antibodies. For this reason, they are used extensively for affinity purification of antibodies from serum or cell culture supernatant, and for capture of immunoprecipitated protein complexes. When Protein A and Protein G microspheres are used as reagents in tests and assays, the immobilized antibodies may be crosslinked to the Protein A- or Protein G-coated support for long-term stability. Protein A and Protein G coated microspheres are available as ~1% solids (w/v) aqueous suspensions in four standard volumes: 1mL, 2mL, 5mL, or 10mL.: