Streptavidin is a bacterially derived biotin-binding protein that reportedly exhibits less nonspecific binding than avidin.
Capacity: Binding activity of streptavidin is determined to be >11 units per mg protein. One unit of binding activity is defined as that amount of protein which binds 1 µg of biotin (Green, N.M., Biochem. J., 89:599,1963)
Form: Streptavidin is provided in lyophilized form in 10 mM phosphate buffered saline, pH 7.4. Reconstitute with 1 ml of distilled or deionized water.
Storage: Store at 4°C.