Thermo Fisher Scientific Inc. announced the launch of the Thermo Scientific Sera-Mag SpeedBeads Blocked-Streptavidin Magnetic Particles for automated immunoassay, immunoprecipitation, DNA/RNA purification and protein purification applications. These uniform, colloidally-stable, monodispersed, nominal 1 µm particles use a non-surfactant, non-protein surface-blocking approach to provide very low non-specific binding and high binding capacity for biotinylated target molecules. The company is showcasing the Thermo Scientific Sera-Mag SpeedBeads Blocked-Streptavidin Magnetic Particles at the Thermo Scientific booth during the 2010 AACC annual meeting.

"The low non-specific binding characteristics of our blocked streptavidin magnetic particles significantly reduce lipids, proteins and other undesirable entities from binding to the particle and interfering with assay precision and specificity. These particles also greatly reduce the need for protein-based blockers that could interfere with downstream applications," said Rick Galloway, director, Particle Technology, Thermo Fisher Scientific.

Based on a patented (#5,648,124) core shell process, Sera-Mag SpeedBeads Blocked-Streptavidin Magnetic Particles feature a unique, cauliflower-like surface with a high biotin-binding capacity that increases overall surface area available for binding.

Typically supplied at one percent solids (10mg/mL) in a 0.05 percent sodium azide water solution, Sera-Mag SpeedBeads Blocked-Streptavidin Magnetic Particles contain two layers of magnetite and a surface encapsulated with a unique polymer and covalently conjugated streptavidin groups. This results in much faster and complete separation in a magnetic field to increase throughput and improve precision in clinical diagnostic assay development. It also enables faster movement through viscous solutions commonly found in molecular biology sample preparation applications.