Magnetic silica particles with high quality streptavidin covalently bonded to the surface of the particle. Applications include immunoassays and capture or purification of biotinylated molecules. Various types of this product are available, with different mean size, streptavidin coating chemistry, and binding capacity. Bigger packages available on request. MagSi-STA Trial kit for protein biochemistry and molecular biology The MagSi-STA Trial kit allows the screening of different types of streptavidin in parallel. The kit is especially useful when required specifications for magnetic beads are not known. This kit includes 1 mL of the 8 different MagSi-STA products and is intended for evaluation purposes during trial phase of developing new assays, or bead replacement in existing assays.