Avidin/Biotin Blocking Kit (SP-2001) blocks all endogenous biotin, biotin receptors, and avidin binding sites present in tissues. This kit is designed for use with biotin/avidin detection systems such as the VECTASTAIN® ABC Kits if avidin or biotinylated reagents bind non-specifically to tissues or proteins. This blocking kit consists of 18 ml of Avidin D and 18 ml of biotin in convenient dropper bottles.Product review on Biocompare.com.