Magnosphere™ MS160/Streptavidin & MS300/Streptavidin is magnetic particles, streptavidin immobilized on the hydrophilic surface. Since the non-specific adsorption of such protein, nucleic acid to the particle surface is kept low, high purity biotin-labeled molecules can be recovered from the sample. The particle surface is coated with a hydrophilic polymer which does not inhibit the enzymatic reaction. Consequently Magnosphere™ MS160/Streptavidin & MS300/Streptavidin can be added to the PCR, quantitative PCR reaction buffer. Also this particle can be used as binding carrier of biotinylated antibody for chemiluminescence enzyme immunoassay.