Streptavidin Coated Surfaces
Streptavidin coated surfaces offer a powerful and universal instrument for binding any biotinylated molecule (Proteins- Peptides-Polysaccharides-Oligonucleotides-DNA fragments-etc.)
Streptavidin is a tetrameric protein (M.W. 60.000) with very high affinity for biotin (Ka=10 15M-1); the bond is the strongest known non-covalent biological interaction.
Biotin is a small molecule which can be conjugated to many proteins without loosing or altering their activity, each protein can bind many biotin molecules.
Since each subunit of streptavidin binds one molecule of biotin, the resulting effect is a great increase of the sensitivity of the assay.
The streptavidin-biotin bonding main features
stability
specificity
affinity
make it useful for special applications of molecules
which do not offer reliable bonding by passive
adsorption or adsorb in an unfavourable orientation.
