Practice question

Biotin tagging exploits exceptionally strong non-covalent interaction between biotin, also called vitamin H, and streptavidin tetramer, with dissociation constant around 10^-15 M, one of the strongest known in biology. Biotinylated bait or target protein can be efficiently captured on streptavidin coated beads, plates, or sensor chips with minimal non-specific binding due to high specificity. Elution may require denaturing conditions. IgG, TEV, and His-tag resin recognize Fc regions, protease sites, and polyhistidine sequences, respectively, and do not bind biotin. Streptavidin capture preserves protein activity and enables downstream functional assays.