Streptavidin-NC

Streptavidin is a tetrameric protein originally derived from the bacterium Streptomyces avidinii. It is renowned for its exceptionally high affinity for biotin (vitamin B7), forming one of the strongest known non-covalent interactions in nature. This strong binding affinity has made streptavidin a crucial component in various biotechnological and diagnostic applications.

Streptavidin-NC is a recombinant form of streptavidin that has been engineered to bind specifically to nitrocellulose membranes. This modification enhances its utility in various laboratory techniques, particularly in immunoassays and western blotting.

Recombinant Streptavidin-NC is produced in Escherichia coli (E. coli) and is a single, non-glycosylated polypeptide chain with a molecular mass of approximately 24 kDa . The protein is purified using affinity chromatography to achieve a purity greater than 90% as determined by SDS-PAGE .

The unique properties of Streptavidin-NC make it highly valuable in several applications:

• Immunoassays: Used as calibrators and controls due to its ability to bind biotinylated molecules with high affinity.
• Western Blotting: Facilitates the detection of biotinylated proteins on nitrocellulose membranes.
• Diagnostics: Integral component in various diagnostic kits due to its stability and strong binding properties.

Streptavidin-NC is stable at 4°C for up to three weeks but should be stored below -18°C for long-term storage to prevent freeze-thaw cycles . The protein is typically supplied in a sterile liquid formulation containing 10mM K₂HPO₄-KH₂PO₄, pH 7.3 .