Merck, E2636-.5ML, ExtrAvidin® –Alkaline Phosphatase

Avidin is a tetrameric or dimeric biotin-binding protein produced in the oviducts of birds, reptiles and amphibians and deposited in the whites of their eggs. It consists of four high affinity binding sites for biotin. ExtrAvidin® is prepared from egg white avidin. It is a modified form of affinity purified avidin with high specific activity of avidin and low background staining of streptavidin. It is a biotin binding protein produced by the bacteria Streptomyces avidinii. ExtrAvidin has been conjugated to Alkaline Phosphatase and is used for various techniques.