Hydrophilic Streptavidin Magnetic Beads from New England Biolabs

Hydrophilic Streptavidin Magnetic Beads are 2 µm superparamagnetic particles covalently coupled to a highly pure form of streptavidin. The beads can be used to capture biotin labeled substrates including antigens, antibodies and nucleic acids (1,2). The strength of the biotin-streptavidin interaction, an association constant (Ka) of 10¹⁵ M^-1 coupled with the low non-specific binding of streptavidin permits captured substrates to be useful as ligands in subsequent experiments including mRNA isolation and the capture of primary or secondary antibodies (3,4).