Streptavidin is a nonglycosylated, tetrameric protein, with each subunit able to bind a single molecule of the vitamin biotin. Streptavidin-biotin bond is the strongest known non-covalent interaction with Kd ~10-15 M. Because streptavidin lacks any carbohydrate modification and has a near-neutral pI, it has the advantage of much lower nonspecific binding than avidin. Streptavidin is broadly used in various applications such as immunoassays, histochemistry, FISH (Fluorescence In Situ Hybridization), flow cytometry, microarrays and blot analysis.
Molecular Mass/ Weight
Storage & stability
The lyophilized powder is stable for years at 4 °C. Reconstitute the powder with desired buffer, such as phosphate-buffered saline. The reconstituted solution will be stable for three months at 4°C if it is added with sodium azide to a final concentration of 2 mM or thimerosal to 0.02%. The reconstituted solution may also be divided into aliquots and stored at -20°C for long-term storage.