Definition of Streptavidin

Streptavidin is a naturally occurring tetrameric protein produced by the bacterium Streptomyces avidinii. The molecular weight of Streptavidin is 75,000 Daltons. The Chemical Abstract Service (CAS) number for Streptavidin is 9013-20-1.

Modern Streptavidin

• A truncated recombinant version of Streptavidin (rSav) is generally what scientists use in their research because it is resistant to protease enzymes. It has a molecular weight of 53,000 Daltons.

Physical Properties

• Streptavidin is usually supplied as a white to off-white lyophilized powder. It is readily soluble in water and has an isoelectric point of 5.

Fire-Related Properties

• Streptavidin is a combustible solid. It requires considerable preheating before burning. It will burn when heated to 1,500 degrees F for five minutes.

Binding

• It can bind very tightly to the vitamin biotin, which makes it useful in a wide variety of molecular biology research techniques.

Uses

• Streptavidin is used for protein purification, protein detection, DNA hybridization and immunological assays. In the future, it might be possible to use Streptavidin for targeted radiation therapy.