streptavidin
noun
strep·ta·vi·din
| \ ˌstrep-ˈtav-əd-ən
, -tə-ˈvīd-ᵊn
\
, -tə-ˈvīd-ᵊn
\
Medical Definition of streptavidin
: a protein similar to avidin that is produced by a bacterium of the genus Streptomyces (S. avidinii), has four identical subunits that each bind tightly to a molecule of biotin, and is used especially in the detection of molecules (as nucleic acids or antibodies) linked to a biotin label