Our new ProActive® protein-coated microspheres are getting rave reviews from customers doing immunoassays, molecular biology and cell work. These generic solid phases dramatically simplify binding to beads, continuing our tradition of supplying only the best microspheres available in the world. (Ask for Technote #51 for a complete listing of available ProActive® products.)

We are very proud of the binding capacity and temperature stability of our streptavidin-coated microspheres. Now available on both superparamagnetic (for easy magnetic separation) and non-magnetic microspheres, ProActive® Streptavidin binds the biotinylated ligand of your choice, (antibody, DNA probe, other binding proteins) quickly and with high affinity. Ask about other avidin coatings, like monomeric avidin or modified avidin. (Technote #55 gives some suggestions for the use of these beads.)

Protein A-coated microspheres specifically bind certain IgGs at the Fc portion of the antibody, resulting in higher activity due to correct orientation. This coating is also available on both magnetic and non-magnetic microspheres. Although we currently offer ProActive® Protein A microspheres, it is not your only choice of IgG binding protein. We can, on a custom basis, coat the microspheres of your choice with native proteins A or G, recombinant forms of proteins A or G (these have deleted albumin binding sequences for reduced non-specific binding), or even with recombinant fusion protein A/G. If you're not sure which protein to use, ask us! (Hints for using ProActive® Protein A microspheres can be found in Technote #58.)

Goat anti-mouse IgG (Fc specific) bound to microspheres picks up mouse IgG and orients it so that the Fab portions are available. By using a secondary antibody system, you can use less primary antibody but get higher activity. ProActive® GAM is our current research product and is now available on our superparamagnetic microspheres; we will soon add GAM non-magnetic polymeric microspheres. If you'd like to participate in the development of ProActive® GAM, please let us know. We'll send you a free sample in exchange for your feedback. More secondary antibody coated beads are on the way, so please contact us with your preferences.

We are convinced that you'll be pleased with the performance of our new ProActive products!

For a complete listing of currently available products, see "Protein Coated Microspheres" in our Microsphere Selection Guide .

And...if the material that you want is not on the list, please ask us. We are making new custom and stock items daily!