Sera-Mag® Magnetic Streptavidin Particles

Sera-Mag Magnetic Streptavidin particles are nominal 1 micron, super-paramagnetic particles of uniform size with covalently bound streptavidin, and have a magnetite content of approximately 40%. Sera-Mag combines the advantages of high surface area, high affinity and high specific activity. These particles are colloidally stable in the absence of a magnetic field, however the particles can be separated rapidly and completely from suspension when a magnetic field is applied. These particles can be used for a variety of applications, including improvement and simplification of ligand binding, molecular biology applications and affinity purifications.

Binding of biotinylated ligands to streptavidin groups on the surface is easily accomplished using standard avidin-biotin technology. In the past, achieving high activity and stable binding of solid phase ligands has been a major difficulty. Compounds which are difficult to attach to microparticle surfaces by conventional means may be amenable to biotinylation. Due to the high affinity of the avidin-biotin reaction, binding biotinylated compounds to Sera-Mag Magnetic Streptavidin may improve specific activity. In such cases, biotinylation may be carried out in either aqueous or organic solvent; then the biotin derivative can be bound to Sera-Mag simply by mixing in appropriate buffer conditions. For example, nucleic acids which adsorb poorly to particle surfaces are readily bound to Sera-Mag Magnetic Streptavidin particles after biotinylation. The use of magnetic microparticles as a solid phase support in immunoassays and molecular biology applications has been well documented. Standard protocols are available to biotinylate a wide range of ligands including proteins, nucleic acids, haptens and peptides.