Streptavidin:
Streptavidin is a tetrameric protein composed of four identical subunits. Each subunit binds one biotin molecule with a KD of ~1 x 10-15 M. The preparation contains an N- and C-terminal shortened variant (core streptavidin) with improved properties concerning homogeneity, solubility, resistance towards proteolytic degradation and accessibility of the biotin binding pocket as compared to native streptavidin. The Avidin-Biotin binding interaction is one of the strongest in nature dissociation constant = 10 -15 M). This interaction is often exploited as a means for enhancing detection in immunohistochemistry and nucleic acid hybridizations. Bio Basic's Streptavidin has a highest specific activity (>17 units/mg protein). This electrophoretically-pure protein is guaranteed free of DNase, RNase and protease activity and is provided as a lyophilized powder. It may be easily conjugated to affinity columns, enzymes, antibodies or nucleic acid probes using any standard protocol