Biotins & streptavidin derivatives

Streptavidin-biotin interaction

The streptavidin-biotin interaction, at a dissociation constant of (Kd) on the order of ~10^-14 mol/L, is one of the strongest non-covalent interactions known in nature, typically occurring between a protein and a ligand.

The complex is resistant to pH, organic solvents and other denaturing agents making this interaction very stable and hence attributes to its importance in a number of biological applications including Western blotting, IHC, ELISA and FACS.